上午9:33 | | | Veronika Baumann, Marius Krumm, Philippe Allard Guérin, Časlav Brukner | | | quant-ph updates on arXiv.org |

One of the most fundamental open problems in physics is the unification of general relativity and quantum theory to a theory of quantum gravity. An aspect that might become relevant in such a theory is that the dynamical nature of causal structure present in general relativity displays quantum uncertainty. This may lead to a phenomenon known as indefinite or quantum causal structure, as captured by the process matrix framework. Due to the generality of that framework, however, for many process matrices there is no clear physical interpretation. A popular approach towards a quantum theory of gravity is the Page-Wootters formalism, which associates to time a Hilbert space structure similar to spatial position. By explicitly introducing a quantum clock, it allows to describe time-evolution of systems via correlations between this clock and said systems encoded in history states. In this paper we combine the process matrix framework with a generalization of the Page-Wootters formalism in which one considers several observers, each with their own discrete quantum clock. We describe how to extract process matrices from scenarios involving such observers with quantum clocks, and analyze their properties. The description via a history state with multiple clocks imposes constraints on the physical implementation of process matrices and on the perspectives of the observers as described via causal reference frames. While it allows for describing scenarios where different definite causal orders are coherently controlled, we explain why certain non-causal processes might not be implementable within this setting.

Consciousness and the Collapse of the Wave Function. (arXiv:2105.02314v1 [quant-ph])

上午9:33 | | | David J. Chalmers, Kelvin J. McQueen | | | quant-ph updates on arXiv.org |

Does consciousness collapse the quantum wave function? This idea was taken seriously by John von Neumann and Eugene Wigner but is now widely dismissed. We develop the idea by combining a mathematical theory of consciousness (integrated information theory) with an account of quantum collapse dynamics (continuous spontaneous localization). Simple versions of the theory are falsified by the quantum Zeno effect, but more complex versions remain compatible with empirical evidence. In principle, versions of the theory can be tested by experiments with quantum computers. The upshot is not that consciousness-collapse interpretations are clearly correct, but that there is a research program here worth exploring.

The EPR paper: a pedagogical approach. (arXiv:2105.02384v1 [quant-ph])

上午9:33 | | | Angel Garcia-Chung | | | quant-ph updates on arXiv.org |

On the seminal paper written by Einstein, Podolsky and Rosen [1], a critique to the completeness of quantum mechanics was posed. Part of the critique consisted in the following argument: if quantum mechanics is complete, then, two physical quantities, with non-commuting operators, can have simultaneous reality. In this paper I aim to provide a pedagogical approach to the notions used in the EPR’s argument.

上午9:33 | | | Johan Beumee, Hershel Rabitz | | | quant-ph updates on arXiv.org |

This paper considers a main particle and an incident particle classical mechanics elastic collision preserving energy and momentum while ignoring the angular momentum, spin or other particle characteristics. The main result of the paper shows that the colliding two particle classical Hamiltonian energy can be represented in four weighted individual particle in symmetric and anti-symmetric (osmotic) terms similar to the quadratic Nelson measure used in the derivation of the Schrodinger wave function. Following Nelson, if the second particle behavior can be captured in a potential and the ingoing and outgoing velocities of the main particle are modelled using stochastic differential equations the motion of the main particle satisfies the Schrodinger’s equation. The diffusion variance of this equation is replaced by a related ratio of masses and the assumed variance. The first example attempts to reconcile this result with quantum mechanics by considering the Schrodinger equation in the presence of only one type of incident particle. The main particle energy levels become multiples of the incident particle and the energy expression for the entire system agrees with quantum mechanics but there are differences with the stochastic equation. The Schrodinger equation can also be used to represent corrections for Newton’s equation and suggests a user profile to be used in the search for Dark Matter. An alternative solution to the collision model also shows relativistic properties as the interactions suggest corrections to the Minkowski equation in Einstein’s Special Relativity. It is also possible to use the classical Schrodinger’s equation both on the main and incident particle simultaneously leading to a correlated set of wave equations with different diffusion parameters.

A Grand Unification of Quantum Algorithms. (arXiv:2105.02859v1 [quant-ph])

上午9:33 | | | John M. Martyn, Zane M. Rossi, Andrew K. Tan, Isaac L. Chuang | | | quant-ph updates on arXiv.org |

Quantum algorithms offer significant speedups over their classical counterparts for a variety of problems. The strongest arguments for this advantage are borne by algorithms for quantum search, quantum phase estimation, and Hamiltonian simulation, which appear as subroutines for large families of composite quantum algorithms. A number of these quantum algorithms were recently tied together by a novel technique known as the quantum singular value transformation (QSVT), which enables one to perform a polynomial transformation of the singular values of a linear operator embedded in a unitary matrix. In the seminal GSLW’19 paper on QSVT [Gily\’en, Su, Low, and Wiebe, ACM STOC 2019], many algorithms are encompassed, including amplitude amplification, methods for the quantum linear systems problem, and quantum simulation. Here, we provide a pedagogical tutorial through these developments, first illustrating how quantum signal processing may be generalized to the quantum eigenvalue transform, from which QSVT naturally emerges. Paralleling GSLW’19, we then employ QSVT to construct intuitive quantum algorithms for search, phase estimation, and Hamiltonian simulation, and also showcase algorithms for the eigenvalue threshold problem and matrix inversion. This overview illustrates how QSVT is a single framework comprising the three major quantum algorithms, thus suggesting a grand unification of quantum algorithms.

Fundamental weight systems are quantum states. (arXiv:2105.02871v1 [math.GT])

上午9:33 | | | David Corfield, Hisham Sati, Urs Schreiber | | | quant-ph updates on arXiv.org |

Weight systems on chord diagrams play a central role in knot theory and Chern-Simons theory; and more recently in stringy quantum gravity. We highlight that the noncommutative algebra of horizontal chord diagrams is canonically a star-algebra, and ask which weight systems are positive with respect to this structure; hence we ask: Which weight systems are quantum states, if horizontal chord diagrams are quantum observables? We observe that the fundamental gl(n)-weight systems on horizontal chord diagrams with N strands may be identified with the Cayley distance kernel at inverse temperature beta=ln(n) on the symmetric group on N elements. In contrast to related kernels like the Mallows kernel, the positivity of the Cayley distance kernel had remained open. We characterize its phases of indefinite, semi-definite and definite positivity, in dependence of the inverse temperature beta; and we prove that the Cayley distance kernel is positive (semi-)definite at beta=ln(n) for all n=1,2,3,… In particular, this proves that all fundamental gl(n)-weight systems are quantum states, and hence so are all their convex combinations. We close with briefly recalling how, under our “Hypothesis H”, this result impacts on the identification of bound states of multiple M5-branes.

上午9:33 | | | gr-qc updates on arXiv.org |

Authors: Ujjal Debnath, Soumak Nag

We assume the anisotropic model of the Universe in the framework of varying speed of light $c$ and varying gravitational constant $G$ theories and study different types of singularities. For the singularity models, we write the scale factors in terms of cosmic time and found some conditions for possible singularities. For future singularities, we assume the forms of varying speed of light and varying gravitational constant. For regularizing big bang singularity, we assume two forms of scale factors: sine model and tangent model. For both the models, we examine the validity of null energy condition and strong energy condition. Start from the first law of thermodynamics, we study the thermodynamic behaviours of $n$ number of Universes (i.e., Multiverse) for (i) varying $c$, (ii) varying $G$ and (iii) both varying $c$ and $G$ models. We found the total entropies for all the cases in the anisotropic Multiverse model. We also found the nature of the Multiverse if total entropy is constant.

De Sitter space-times in Entangled Relativity. (arXiv:2011.14633v2 [gr-qc] UPDATED)

上午9:33 | | | gr-qc updates on arXiv.org |

Authors: Olivier Minazzoli

It is argued that de Sitter space-times might be solutions of entangled relativity once the quantum trace anomaly from matter fields in curved space-times is taken into account. This hypothesis would be an elegant solution to the acceleration of the expansion of the universe within the rigid framework of entangled relativity.

Varieties of Dispositional Essentialism about Natural Laws

2021年5月6日 星期四 上午9:00 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Hirèche, Salim (2020) Varieties of Dispositional Essentialism about Natural Laws. [Preprint]

Lost Horizon? – Modeling Black Holes in String Theory

2021年5月4日 星期二 下午3:25 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Huggett, Nick and Matsubara, Keizo (2020) Lost Horizon? – Modeling Black Holes in String Theory. [Preprint]

Epistemic Modality, Mind, and Mathematics

2021年5月4日 星期二 下午3:24 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Khudairi, Hasen (2017) Epistemic Modality, Mind, and Mathematics. [Preprint]

The Math is not the Territory: Navigating the Free Energy Principle

2021年5月4日 星期二 上午7:25 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Andrews, Mel (2021) The Math is not the Territory: Navigating the Free Energy Principle. [Preprint]

Feyerabend’s rule and dark matter

2021年5月3日 星期一 上午8:00 | | | Latest Results for Synthese |

**Abstract**

Paul Feyerabend argued that theories can be faced with experimental anomalies whose refuting character can only be recognized by developing alternatives to the theory. The alternate theory must explain the experimental results without contrivance and it must also be supported by independent evidence. I show that the situation described by Feyerabend arises again and again in experiments or observations that test the postulates in the standard cosmological model relating to dark matter. The alternate theory is Milgrom’s modified dynamics (MOND). I discuss three examples: the failure to detect dark-matter particles in laboratory experiments; the lack of evidence for dark-matter sub-haloes and the dwarf galaxies that are postulated to inhabit them; and the failure to confirm the predicted orbital decay of Milky Way satellite galaxies and other systems due to dynamical friction against the dark matter. In each case, Feyerabend’s criterion directs us to interpret the experimental or observational results as an indirect refutation of the standard cosmological model in favor of Milgrom’s theory.

Thinking about Progress: From Science to Philosophy

2021年5月3日 星期一 上午1:40 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Dellsén, Finnur and Lawler, Insa and Norton, James (2021) Thinking about Progress: From Science to Philosophy. [Preprint]

2021年5月1日 星期六 下午5:18 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Pradeu, Thomas and Lemoine, Maël and Khelfaoui, Mahdi and Gingras, Yves (2021) Philosophy in Science: Can philosophers of science permeate through science and produce scientific knowledge? [Preprint]

]]>上午10:02 | | | Brian R. La Cour | | | quant-ph updates on arXiv.org |

The Greenberger-Horne-Zeilinger (GHZ) puzzle has been used to study quantum nonlocality and provide an all-or-nothing, no-go theorem for local hidden-variable models. Recent experiments using coincident-detected entangled photons prepared in a three-particle GHZ state have been used to test quantum nonlocality, but fail to rule out local realism due to a reliance on the fair-sampling hypothesis and insufficient detection efficiency. This paper describes a physically motivated local hidden-variable model based on amplitude-threshold detection that is capable of producing similar results. Detection efficiencies for the model are within the bounds permitted for local realism and, interestingly, exhibit statistical correlations between detectors, even when the detection events are spacelike separated. Increasing the detection threshold improves agreement with the ideal quantum predictions at the cost of decreased detection efficiency. A curious emergent feature of the model is that detection efficiencies may depend upon which observables are chosen for measurement.

上午10:02 | | | Somshubhro Bandyopadhyay, Saronath Halder | | | quant-ph updates on arXiv.org |

Quantum nonlocality has different manifestations that, in general, are revealed by local measurements of the parts of a composite system. In this paper, we focus on the kind of nonlocality that arises from a set of orthogonal states that cannot be perfectly distinguished by local operations and classical communication (LOCC). Such a set is deemed nonlocal, for a joint measurement on the whole system is necessary for perfect discrimination of the states with certainty. On the other hand, a set of orthogonal states that can be perfectly distinguished by LOCC is believed to be devoid of nonlocal properties. In this paper, we study the properties of orthogonal sets that are locally distinguishable and without local redundancy. The latter implies that they become nonorthogonal on discarding one or more subsystems. We show that such a set may be locally converted, with certainty, into another orthogonal set of states that cannot be locally distinguished. Notably, the cardinality does not change in the process. We illustrate this with several examples. We also provide a partial characterization of those that do not have this property. Conceptually, our result can be viewed as activation of nonlocality in the scenario of local state discrimination. We also suggest an application, namely, local hiding of information, that allows us to locally hide the locally available information without losing any part. Once hidden, the information in its entirety can only be retrieved using entanglement.

上午10:02 | | | physics.hist-ph updates on arXiv.org |

Authors: Sylvio R Bistafa

This is a translation from Latin of ‘De novo oscillationum genere’, which was motivated by Krafft’s accidental observation of a suspended clock setting itself in constant motion as a pendulum. This publication, in turn, motivated Euler to write ‘De novo genere oscillationum’, in which Euler derived for the first time, the differential equation for the (undamped) simple harmonic oscillator under harmonic excitation.

Cosmology from pregeometry. (arXiv:2104.14013v1 [gr-qc])

上午10:02 | | | gr-qc updates on arXiv.org |

Authors: C. Wetterich

We discuss cosmological solutions for a diffeomorphism invariant gauge theory of the non-compact Lorentz group $SO(1,3)$. Besides the gauge bosons our model of pregeometry contains a vector field in the vector representation of $SO(1,3)$ and a scalar singlet. General relativity and variable gravity emerge as effective theories for large distances and times in Planck units. We propose an approximation to the effective action with up to two derivatives. For a suitable range of parameters the universe approaches for large times stable Minkowski space. For late cosmology the model predicts dynamical dark energy and provides for a candidate for dark matter. Early cosmology is characterized by an inflationary epoch. The beginning of the universe in the infinite past is great emptiness, corresponding to an ultraviolet fixed point with the associated quantum scale symmetry. The beginning universe is a vacuum state with vanishing expectation values and finite non-vanishing correlation functions for the fluctuations of all fields. There is no physical big bang singularity.

Testing $f(Q, T)$ gravity models that reduce to $\Lambda CDM$. (arXiv:2104.14065v1 [gr-qc])

上午10:02 | | | gr-qc updates on arXiv.org |

Authors: Antonio Nájera, Amanda Fajardo

We tested four $f(Q,T)$ models in an extension of symmetric teleparallel gravity whose Friedmann equations reduce to $\Lambda CDM$ for certain parameters. Using low-redshift data we found that all our models were 2$\sigma$ consistent with $\Lambda CDM$ and the Hubble constant value were $\sigma$ consistent with the one of the SH0ES collaboration and at $12\sigma$ tension with the one of the Planck Collaboration. To see whether one of our models can challenge $\Lambda CDM$ at a background perspective, we computed the Bayesian evidence for our four models and $\Lambda CDM$. The concordance model was preferred over all our $f(Q,T)$ alternate models, showing a weak preference against models $f(Q,T) = -Q/G_N + bT$ and $-(Q+2\Lambda)/G_N + bT$ and a substantial preference against models $f(Q,T) = -(Q+2H_0c(Q/(6H_0^2))^{n+1})/G_N + bT$ and $f(Q,T) = -(Q+2H_0c(Q/(6H_0^2))^{n+1} + 2\Lambda)/G_N + bT$. Our models were successful to reproduce $\Lambda CDM$ acceleration from low redshifts.

A Measure of Classicality. (arXiv:2104.14465v1 [gr-qc])

上午10:02 | | | gr-qc updates on arXiv.org |

Authors: James B. Hartle (UCSB), Murray Gell-Mann (deceased)

A striking feature of our fundamentally indeterministic quantum universe is its quasiclassical realm — the wide range of time place and scale in which the deterministic laws of classical physics hold. Our quasiclassical realmis an emergent feature of the fundamental theories of our universe’s quantum state and dynamics. There are many types of quasiclassical realms our Universe could exhibit characterized by different variables, different levels of coarse-graining, different locations in spacetime, different classical physics, and different levels of classicality.We propose a measure of classicality for quasiclassical realms, We speculate on the observable consequences of different levels of classicality especially for information gathering and utilizing systems (IGUSes) such ourselves as observers of the Universe.

Spontaneous Lorentz violation and asymptotic flatness. (arXiv:2103.07611v2 [gr-qc] UPDATED)

上午10:02 | | | gr-qc updates on arXiv.org |

Authors: Yuri Bonder, Christian Peterson

The Standard Model Extension (SME) is a generic parametrization for Lorentz violation and the phenomenological consequences of the minimal gravity sector of the SME are usually studied using a post-Newtonian expansion that requires spacetime to be asymptotically flat. However, there is a term in this sector for which these approximations are unable to make predictions; this is known as the $t$ puzzle. The present paper studies a model of spontaneous Lorentz violation in the minimal gravity sector of the SME in a static and spherically symmetric situation, when no additional matter fields are present. It is shown that, under the above mentioned assumptions, $t$ is the only term in the minimal gravity sector for which no asymptotically flat solutions exist. This stems from the fact that the $t$ term fixes the asymptotic behavior of all the pieces of the curvature tensor.

Beables, Primitive Ontology and Beyond: How Theories Meet the World

2021年4月30日 星期五 上午3:15 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Oldofredi, Andrea (2021) Beables, Primitive Ontology and Beyond: How Theories Meet the World. [Preprint]

Perennial Symmetry Arguments: Aristotle’s Heavenly Cosmology and Noether’s First Theorem

2021年4月30日 星期五 上午3:13 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Miller, Ryan (2019) Perennial Symmetry Arguments: Aristotle’s Heavenly Cosmology and Noether’s First Theorem. Proceedings of the American Catholic Philosophical Association, 93.

Must Hidden Variables Theories Be Contextual? Kochen & Specker meet von Neumann and Gleason

2021年4月30日 星期五 上午3:12 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Acuña, Pablo (2021) Must Hidden Variables Theories Be Contextual? Kochen & Specker meet von Neumann and Gleason. European Journal for Philosophy of Science, 41. ISSN 1879-4912

The Maxim of Probabilism — with special regard to Reichenbach

2021年4月30日 星期五 上午3:12 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Rédei, Miklós and Gyenis, Zalán (2021) The Maxim of Probabilism — with special regard to Reichenbach. [Preprint]

Learning models of quantum systems from experiments

2021年4月29日 星期四 上午8:00 | | | Anthony Laing | | | Nature Physics – Issue – nature.com science feeds |

Nature Physics, Published online: 29 April 2021; doi:10.1038/s41567-021-01201-7

Quantum systems make it challenging to determine candidate Hamiltonians from experimental data. An automated protocol is presented and its capabilities to infer the correct Hamiltonian are demonstrated in a nitrogen-vacancy centre set-up.

Atomtronic Matter-Wave Lensing

2021年4月28日 星期三 下午6:00 | | | Saurabh Pandey, Hector Mas, Georgios Vasilakis, and Wolf von Klitzing | | | PRL: General Physics: Statistical and Quantum Mechanics, Quantum Information, etc. |

Author(s): Saurabh Pandey, Hector Mas, Georgios Vasilakis, and Wolf von Klitzing

A new “lensing” technique counters the spreading of an ultracold cloud of atoms inside a tiny waveguide.

[Phys. Rev. Lett. 126, 170402] Published Wed Apr 28, 2021

2021年4月27日 星期二 下午6:00 | | | Salambô Dago, Jorge Pereda, Nicolas Barros, Sergio Ciliberto, and Ludovic Bellon | | | PRL: General Physics: Statistical and Quantum Mechanics, Quantum Information, etc. |

Author(s): Salambô Dago, Jorge Pereda, Nicolas Barros, Sergio Ciliberto, and Ludovic Bellon

The Landauer principle states that at least kBTln2 of energy is required to erase a 1-bit memory, with kBT the thermal energy of the system. We study the effects of inertia on this bound using as one-bit memory an underdamped micromechanical oscillator confined in a double-well potential created by …

[Phys. Rev. Lett. 126, 170601] Published Tue Apr 27, 2021

Preparation in Bohmian Mechanics

2021年4月25日 星期日 下午3:59 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

ROVELLI, Carlo (2021) Preparation in Bohmian Mechanics. [Preprint]

Probability and Irreversibility in Modern Statistical Mechanics: Classical and Quantum

2021年4月25日 星期日 下午3:57 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Wallace, David (2016) Probability and Irreversibility in Modern Statistical Mechanics: Classical and Quantum. [Preprint]

]]>上午9:11 | | | M. Wakamatsu, Y. Kitadono, L.-P. Zou, P.-M. Zhang | | | quant-ph updates on arXiv.org |

As is widely-known, the eigen-functions of the Landau problem in the symmetric gauge are specified by two quantum numbers. The first is the familiar Landau quantum number $n$, whereas the second is the magnetic quantum number $m$, which is the eigen-value of the canonical orbital angular momentum (OAM) operator of the electron. The eigen-energies of the system depend only on the first quantum number $n$, and the second quantum number $m$ does not correspond to any direct observables. This seems natural since the canonical OAM is generally believed to be a {\it gauge-variant} quantity, and observation of a gauge-variant quantity would contradict a fundamental principle of physics called the {\it gauge principle}. In recent researches, however, Bliohk et al. analyzed the motion of helical electron beam along the direction of a uniform magnetic field, which was mostly neglected in past analyses of the Landau states. Their analyses revealed highly non-trivial $m$-dependent rotational dynamics of the Landau electron, but the problem is that their papers give an impression that the quantum number $m$ in the Landau eigen-states corresponds to a genuine observable. This compatibility problem between the gauge principle and the observability of the quantum number $m$ in the Landau eigen-states was attacked in our previous letter paper. In the present paper, we try to give more convincing answer to this delicate problem of physics, especially by paying attention not only to the {\it particle-like} aspect but also to the {\it wave-like} aspect of the Landau electron.

上午9:11 | | | Davide Fermi, Livio Pizzocchero (Universita’ di Milano) | | | quant-ph updates on arXiv.org |

We comment on the recent work [1], and on its relations with our papers [2,3] cited therein. In particular we show that, contrarily to what stated in [1], the Casimir energy density determined therein in the case of a single delta-like singularity coincides with the energy density obtained previously in our paper [2] using a different approach.

上午9:11 | | | physics.hist-ph updates on arXiv.org |

Authors: Moorad Alexanian

Both Albert Einstein and Erwin Schr\”{o}dinger have defined what science is. Einstein includes not only physics, but also all natural sciences dealing with both organic and inorganic processes in his definition of science. According to Schr\”{o}dinger, the present scientific worldview is based on the two basic attitudes of comprehensibility and objectivation. On the other hand, the notion of religion is quite equivocal and unless clearly defined will easily lead to all sorts of misunderstandings. Does science, as defined, encompass the whole of reality? More importantly, what is the whole of reality and how do we obtain data for it? The Christian worldview considers a human as body, mind, and spirit (soul), which is consistent with Cartesian ontology of only three elements: matter, mind, and God. Therefore, is it possible to give a precise definition of science showing that the conflicts are actually apparent and not real?

The Mereology of Thermodynamic Equilibrium. (arXiv:2104.11140v1 [physics.hist-ph])

上午9:11 | | | physics.hist-ph updates on arXiv.org |

Authors: Michael te Vrugt

The special composition question (SCQ), which asks under which conditions objects compose a further object, establishes a central debate in modern metaphysics. Recent successes of inductive metaphysics, which studies the implications of the natural sciences for metaphysical problems, suggest that insights into the SCQ can be gained by investigating the physics of composite systems. In this work, I show that the minus first law of thermodynamics, which is concerned with the approach to equilibrium, leads to a new approach to the SCQ, the thermodynamic composition principle (TCP): Multiple systems in (generalized) thermal contact compose a single system. This principle, which is justified based on a systematic classification of possible mereological models for thermodynamic systems, can form the basis of an inductive argument for universalism. A formal analysis of the TCP is provided on the basis of mereotopology, which is a combination of mereology and topology. Here, “thermal contact” can be analyzed using the mereotopological predicate “self-connectedness”. Self-connectedness has to be defined in terms of mereological sums to ensure that scattered objects cannot be self-connected.

上午9:10 | | | gr-qc updates on arXiv.org |

Authors: Ibrahima Bah, Iosif Bena, Pierre Heidmann, Yixuan Li, Daniel R. Mayerson

We construct a family of non-supersymmetric extremal black holes and their horizonless microstate geometries in four dimensions. The black holes can have finite angular momentum and an arbitrary charge-to-mass ratio, unlike their supersymmetric cousins. These features make them and their microstate geometries astrophysically relevant. Thus, they provide interesting prototypes to study deviations from Kerr solutions caused by new horizon-scale physics. In this paper, we compute the gravitational multipole structure of these solutions and compare them to Kerr black holes. The multipoles of the black hole differ significantly from Kerr as they depend non-trivially on the charge-to-mass ratio. The horizonless microstate geometries have the same multipoles as their corresponding black hole, with small deviations set by the scale of their microstructure.

Beyond the Equivalence Principle: Gravitational Magnetic Monopoles. (arXiv:2104.11063v1 [gr-qc])

上午9:10 | | | gr-qc updates on arXiv.org |

Authors: Mario Novello, Angelo E. S. Hartmann

We review the hypothesis of the existence of gravitational magnetic monopoles (H-pole for short) defined in analogy with the Dirac’s hypothesis of magnetic monopoles in electrodynamics. These hypothetical dual particles violate the equivalence principle and are accelerated by a gravitational field. We propose an expression for the gravitational force exerted upon an H-pole. According to GR ordinary matter (which we call E-poles) follows geodesics in a background metric. The dual H-poles follows geodesics in an effective metric.

上午9:10 | | | gr-qc updates on arXiv.org |

Authors: I-Chin Wang

We investigate the interaction between a moving detector and a quantum field, especially about how the trajectory of the detector would affect the vacuum fluctuations when the detector is moving in a quantum field (Unruh effect). We focus on two moving detectors system for the future application in quantum teleportation. We find that the trajectory of an uniformly accelerated detector in Rindler space can’t be extended to the trajectory that a detector moves at constant velocity. Based on the past work, we redo the calculations and find that a term is missing in the past calculations, also we find that there are some restrictions on the values for the parameters in the solutions. Besides, without including the missing term, the variance from the quantum field for the inertial detector will be zero and is unlikely for such system. Combining all these points, there is a difference on the two-point correlation function between the inertial detector and accelerated detector in early-time region. The influence from proper acceleration can be seen in the two-point correlation functions. This might play a role in the quantum teleportation process and worth to study thoroughly.

2021年4月23日 星期五 上午8:00 | | | Latest Results for Synthese |

**Abstract**

The bare theory is a no-collapse version of quantum mechanics which predicts certain puzzling results for the introspective beliefs of human observers of superpositions. The bare theory can be interpreted to claim that an observer can form false beliefs about the outcome of an experiment which produces a superpositional result. It is argued that, when careful consideration is given to the observer’s belief states and their evolution, the observer does not end up with the beliefs claimed. This result leads to questions about whether there can be any allure for no-collapse theories as austere as the bare theory.

Simulating the Same Physics with Two Distinct Hamiltonians

2021年4月22日 星期四 下午6:00 | | | Karol Gietka, Ayaka Usui, Jianqiao Deng, and Thomas Busch | | | PRL: General Physics: Statistical and Quantum Mechanics, Quantum Information, etc. |

Author(s): Karol Gietka, Ayaka Usui, Jianqiao Deng, and Thomas Busch

A new framework allows one to use a quantum simulation of one Hamiltonian to study another.

[Phys. Rev. Lett. 126, 160402] Published Thu Apr 22, 2021

Non-equilibrium Thermodynamics and the Free Energy Principle in Biology

2021年4月22日 星期四 下午3:53 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Palacios, Patricia and Colombo, Matteo (2021) Non-equilibrium Thermodynamics and the Free Energy Principle in Biology. [Preprint]

Russell’s The Analysis of Matter as the First Book on Quantum Gravity

2021年4月21日 星期三 下午3:24 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Mikki, Said (2021) Russell’s The Analysis of Matter as the First Book on Quantum Gravity. [Preprint]

The Democratization of Science

2021年4月21日 星期三 下午3:23 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Kurtulmus, Faik (2021) The Democratization of Science. [Preprint]

Perspectival QM and Presentism: a New Paradigm

2021年4月21日 星期三 下午3:21 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Merriam, Paul (2021) Perspectival QM and Presentism: a New Paradigm. [Preprint]

Exact Thermalization Dynamics in the “Rule 54” Quantum Cellular Automaton

2021年4月19日 星期一 下午6:00 | | | Katja Klobas, Bruno Bertini, and Lorenzo Piroli | | | PRL: General Physics: Statistical and Quantum Mechanics, Quantum Information, etc. |

Author(s): Katja Klobas, Bruno Bertini, and Lorenzo Piroli

New studies provide analytical descriptions and exact solutions for various aspects of thermodynamics in quantum many-body systems.

[Phys. Rev. Lett. 126, 160602] Published Mon Apr 19, 2021

Philosophy of Science in China: Politicized, De-politicized, and Re-politicized

2021年4月19日 星期一 下午3:06 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Guo, Yuanlin and Ludwig, David (2021) Philosophy of Science in China: Politicized, De-politicized, and Re-politicized. [Preprint]

2021年4月19日 星期一 下午3:05 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Norton, John D. and Parker, Matthew W. (2021) An Infinite Lottery Paradox. [Preprint]

A new paradox and the reconciliation of Lorentz and Galilean transformations

2021年4月19日 星期一 上午8:00 | | | Latest Results for Synthese |

**Abstract**

One of the most debated problems in the foundations of the special relativity theory is the role of conventionality. A common belief is that the Lorentz transformation is correct but the Galilean transformation is wrong (only approximately correct in low speed limit). It is another common belief that the Galilean transformation is incompatible with Maxwell equations. However, the “principle of general covariance” in general relativity makes any spacetime coordinate transformation equally valid. This includes the Galilean transformation as well. This renders a new paradox. This new paradox is resolved with the argument that the Galilean transformation is equivalent to the Lorentz transformation. The resolution of this new paradox also provides the most straightforward resolution of an older paradox which is due to Selleri in (Found Phys Lett 10:73–83, 1997). I also present a consistent electrodynamics formulation including Maxwell equations and electromagnetic wave equations under the Galilean transformation, in the exact form for any high speed, rather than in low speed approximation. Electrodynamics in rotating reference frames is rarely addressed in textbooks. The presented formulation of electrodynamics under the Galilean transformation even works well in rotating frames if we replace the constant velocity \(\mathbf {v}\) with \(\mathbf {v}=\varvec{\omega }\times \mathbf {r}\) . This provides a practical tool for applications of electrodynamics in rotating frames. When electrodynamics is concerned, between two inertial reference frames, both Galilean and Lorentz transformations are equally valid, but the Lorentz transformation is more convenient. In rotating frames, although the Galilean electrodynamics does not seem convenient, it could be the most convenient formulation compared with other transformations, due to the intrinsic complex nature of the problem.

2021年4月19日 星期一 上午8:00 | | | Latest Results for Synthese |

**Abstract**

Scientific disputes about how often different processes or patterns occur are *relative frequency controversies*. These controversies occur across the sciences. In some areas—especially biology—they are even the dominant mode of dispute. Yet they depart from the standard picture of what a scientific controversy is like. In fact, standard philosophical accounts of scientific controversies suggest that relative frequency controversies are irrational or lacking in epistemic value. This is because standard philosophical accounts of scientific controversies often assume that in order to be rational, a scientific controversy must (a) reach a resolution and (b) be about a scientifically interesting question. Relative frequency controversies rarely reach a resolution, however, and some scientists and philosophers are skeptical that these controversies center on scientifically interesting questions. In this paper, I provide a novel account of the epistemic contribution that relative frequency controversies make to science. I show that these controversies are rational in the sense of furthering the epistemic aims of the scientific communities in which they occur. They do this despite rarely reaching a resolution, and independent of whether the controversies are about scientifically interesting questions. This means that assumptions (a) and (b) about what is required for a controversy to be rational are wrong. Controversies do not need to reach a resolution in order to be rational. And they do not need to be about anything scientifically interesting in order to make valuable epistemic contributions to science.

Barad, Bohr, and quantum mechanics

2021年4月18日 星期日 上午8:00 | | | Latest Results for Synthese |

**Abstract**

The last decade has seen an increasing number of references to quantum mechanics in the humanities and social sciences. This development has in particular been driven by Karen Barad’s agential realism: a theoretical framework that, based on Niels Bohr’s interpretation of quantum mechanics, aims to inform social theorizing. In dealing with notions such as agency, power, and embodiment as well as the relation between the material and the discursive level, the influence of agential realism in fields such as feminist science studies and posthumanism has been profound. However, no one has hitherto paused to assess agential realism’s proclaimed quantum mechanical origin including its relation to the writings of Niels Bohr. This is the task taken up here. We find that many of the implications that agential realism allegedly derives from a Bohrian interpretation of quantum mechanics dissent from Bohr’s own views and are in conflict with those of other interpretations of quantum mechanics. Agential realism is at best consistent with quantum mechanics and consequently, it does not capture what quantum mechanics in any strict sense implies for social science or any other domain of inquiry. Agential realism may be interesting and thought provoking from the perspective of social theorizing, but it is neither sanctioned by quantum mechanics nor by Bohr’s authority. This conclusion not only holds for agential realism in particular, it also serves as a general warning against the other attempts to use quantum mechanics in social theorizing.

The landscape and the multiverse: What’s the problem?

2021年4月18日 星期日 上午8:00 | | | Latest Results for Synthese |

**Abstract**

As a candidate theory of quantum gravity, the popularity of string theory has waxed and waned over the past four decades. One current source of scepticism is that the theory can be used to derive, depending upon the input geometrical assumptions that one makes, a vast range of different quantum field theories, giving rise to the so-called landscape problem. One apparent way to address the landscape problem is to posit the existence of a multiverse; this, however, has in turn drawn heightened attention to questions regarding the empirical testability and predictivity of string theory. We argue first that the landscape problem relies on dubious assumptions and does not motivate a multiverse hypothesis. Nevertheless, we then show that the multiverse hypothesis is scientifically legitimate and could be coupled to string theory for other empirical reasons. Looking at various cosmological approaches, we offer an empirical criterion to assess the scientific status of multiverse hypotheses

The First Droplet in a Cloud Chamber Track

Jonathan F. Schonfeld

Foundations of Physics volume 51, Article number: 47 (2021)

**Abstract**

In a cloud chamber, the quantum measurement problem amounts to explaining the first droplet in a charged-particle track; subsequent droplets are explained by Mott’s 1929 wave-theoretic argument about collision-induced wavefunction collimation. I formulate a mechanism for how the first droplet in a cloud chamber track arises, making no reference to quantum measurement axioms. I look specifically at tracks of charged particles emitted in the simplest slow decays, because I can reason about rather than guess the form that wave packets take. The first visible droplet occurs when a randomly occurring, barely-subcritical vapor droplet is pushed past criticality by ionization triggered by the faint wavefunction of the emitted charged particle. This is possible because potential energy incurred when an ionized vapor molecule polarizes the other molecules in a droplet can balance the excitation energy needed for the emitted charged particle to create the ion in the first place. This degeneracy is a singular condition for Coulombic scattering, leading to infinite or near-infinite ionization cross sections, and from there to an emergent Born rule in position space, but not an operator projection as in the projection postulate. Analogous mechanisms may explain canonical quantum measurement behavior in detectors such as ionization chambers, proportional counters, photomultiplier tubes or bubble chambers. This work is important because attempts to understand canonical quantum measurement behavior and its limitations have become urgent in view of worldwide investment in quantum computing and in searches for super-rare processes (e.g., proton decay).

]]>上午10:31 | | | Mark G. Kuzyk | | | quant-ph updates on arXiv.org |

Students in quantum mechanics class are taught that the wave function contains all knowable information about an isolated system. Later in the course, this view seems to be contradicted by the mysterious density matrix, which introduces a new set of probabilities in addition to those that are built into the wave function. This paper brings attention to the fact that the density matrix can be reconciled with the underlying quantum-mechanical description using a two-particle entangled state with a one-particle subsystem as the simplest illustration of the basic principle. The extra-quantum probabilities are traced to the coefficients of superposition of the quantum state vector and the seemingly irreversible exponential population decay is shown to be compatible with the unitary time evolution of a pure state when the two particles interact. The two-particle universe thus provides the student with a tool for understanding how the density operator, with all its richness, emerges from quantum mechanics.

Twistor action for general relativity. (arXiv:2104.07031v1 [hep-th])

上午10:31 | | | gr-qc updates on arXiv.org |

Authors: Atul Sharma

We reformulate Euclidean general relativity without cosmological constant as an action governing the complex structure of twistor space. Extending Penrose’s non-linear graviton construction, we find a correspondence between twistor spaces with partially integrable almost complex structures and four-dimensional space-times with off-shell metrics. Using this, we prove that our twistor action reduces to Plebanski’s action for general relativity via the Penrose transform. This should lead to new insights into the geometry of graviton scattering as well as to the derivation of computational tools like gravitational MHV rules.

上午10:31 | | | gr-qc updates on arXiv.org |

Authors: Brett McInnes

The Weak Gravity Conjecture requires that it be possible for all (classically stable) extremal black holes to decay. The “black hole version” of the conjecture requires that it should be possible for this to occur through the emission of smaller black holes. We consider this version in the case of extremal AdS$_4$-Kerr-Newman black holes which are stable against a superradiant instability. One finds that the emitted black hole must be very exotic, having a direction-dependent causal structure. This is independent of the question as to whether the emitted black hole necessarily violates classical Cosmic Censorship. When the system is embedded in string theory, however, we find that it (probably) does.

Born-Oppenheimer meets Wigner-Weyl in Quantum Gravity. (arXiv:2104.07480v1 [gr-qc])

上午10:31 | | | gr-qc updates on arXiv.org |

Authors: A. Y. Kamenshchik, A. Tronconi, G. Venturi

Starting from a Born-Oppenheimer decomposition of the Wheeler-DeWitt equation for the quantum cosmology of the matter-gravity system, we have performed a Wigner-Weyl transformation and obtained equations involving a Wigner function for the scale factor and its conjugate momentum. This has allowed us to study in more detail than previously the approach to the classical limit of gravitation and the way time emerges in such a limit. To lowest order we reproduce the Friedmann equation and the previously obtained equation for the evolution of matter. We also obtain expressions for higher order corrections to the semi-classical limit.

Losing the trace to find dynamical Newton or Planck constants. (arXiv:2011.07055v2 [gr-qc] UPDATED)

上午10:31 | | | gr-qc updates on arXiv.org |

Authors: Pavel Jiroušek, Keigo Shimada, Alexander Vikman, Masahide Yamaguchi

We show that promoting the trace part of the Einstein equations to a trivial identity results in the Newton constant being an integration constant. Thus, in this formulation the Newton constant is a global dynamical degree of freedom which is also a subject to quantization and quantum fluctuations. This is similar to what happens to the cosmological constant in the unimodular gravity where the trace part of the Einstein equations is lost in a different way. We introduce a constrained variational formulation of these modified Einstein equations. Then, drawing on analogies with the Henneaux-Teitelboim action for unimodular gravity, we construct different general-covariant actions resulting in these dynamics. The inverse of dynamical Newton constant is canonically conjugated to the Ricci scalar integrated over spacetime. Surprisingly, instead of the dynamical Newton constant one can formulate an equivalent theory with a dynamical Planck constant. Finally, we show that an axion-like field can play a role of the gravitational Newton constant or even of the quantum Planck constant.

Modified gravity: a unified approach. (arXiv:2103.15906v2 [gr-qc] UPDATED)

上午10:31 | | | gr-qc updates on arXiv.org |

Authors: Christian G. Boehmer, Erik Jensko

Starting from the original Einstein action, sometimes called the Gamma squared action, we propose a new setup to formulate modified theories of gravity. This can yield a theory with second order field equations similar to those found in other popular modified gravity models. Using a more general setting the theory gives fourth order equations. This model is based on the metric alone and does not require more general geometries. It is possible to show that our new theory and the recently proposed $f(Q)$ gravity models are equivalent at the level of the action and at the level of the field equations, provided that appropriate boundary terms are taken into account. Our theory can also match up with $f(R)$ gravity which is an expected result. Perhaps more surprisingly, we can also show that this equivalence extends to $f(T)$ gravity at the level of the action and its field equations, provided that appropriate boundary terms are taken in account. While these three theories are conceptually different and are based on different geometrical settings, we can establish the necessary conditions under which their field equations are indistinguishable. The final part requires matter to couple minimally to gravity. Through this work we emphasise the importance played by boundary terms which are at the heart of our approach.

上午10:31 | | | gr-qc updates on arXiv.org |

We focus on two types of coherent states, the coherent states of multi graviton states and the coherent states of giant graviton states, in the context of gauge/gravity correspondence. We conveniently use a phase shift operator and its actions on the superpositions of these coherent states. We find $N$-state Schrodinger cat states which approach the one-row Young tableau states, with fidelity between them asymptotically reaches 1 at large $N$. The quantum Fisher information of these states is proportional to the variance of the excitation energy of the underlying states, and characterizes the localizability of the states in the angular direction in the phase space. We analyze the correlation and entanglement between gravitational degrees of freedom using different regions of the phase space plane in bubbling AdS. The correlation between two entangled rings in the phase space plane is related to the area of the annulus between the two rings. We also analyze two types of noisy coherent states, which can be viewed as interpolated states that interpolate between a pure coherent state in the noiseless limit and a maximally mixed state in the large noise limit.

Scientific Conclusions Need Not Be Accurate, Justified, or Believed by their Authors

上午2:27 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Dang, Haixin and Bright, Liam Kofi (2021) Scientific Conclusions Need Not Be Accurate, Justified, or Believed by their Authors. [Preprint]

Numerical instability and dynamical systems

上午2:25 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Ardourel, Vincent and Jebeile, Julie (2021) Numerical instability and dynamical systems. [Preprint]

Geometric objects and perspectivalism

上午2:25 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Read, James (2021) Geometric objects and perspectivalism. [Preprint]

Tunnelling Times in Quantum Mechanics

上午2:23 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Puleston, James (2020) Tunnelling Times in Quantum Mechanics. UNSPECIFIED, Cambridge.

Localizable Particles in the Classical Limit of Quantum Field Theory

2021年4月14日 星期三 下午2:38 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Feintzeig, Benjamin and Librande, Jonah and Soiffer, Rory (2021) Localizable Particles in the Classical Limit of Quantum Field Theory. Foundations of Physics.

2021年4月14日 星期三 下午2:37 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Loewer, Barry (2021) Are Humean Laws Flukes? [Preprint]

Quantum superpositions and the measurement problem

2021年4月13日 星期二 下午2:09 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Henriksson, Andreas (2021) Quantum superpositions and the measurement problem. [Preprint]

Fidelity and mistaken identity for symplectic quantum states

2021年4月13日 星期二 下午2:08 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Henriksson, Andreas (2021) Fidelity and mistaken identity for symplectic quantum states. [Preprint]

2021年4月13日 星期二 上午8:00 | | | Latest Results for Synthese |

**Abstract**

Predictive processing theories are increasingly popular in philosophy of mind; such process theories often gain support from the Free Energy Principle (FEP)—a normative principle for adaptive self-organized systems. Yet there is a current and much discussed debate about conflicting philosophical interpretations of FEP, e.g., representational versus non-representational. Here we argue that these different interpretations depend on implicit assumptions about what qualifies (or fails to qualify) as representational. We deploy the Free Energy Principle (FEP) instrumentally to distinguish four main notions of representation, which focus on organizational, structural, content-related and functional aspects, respectively. The various ways that these different aspects matter in arriving at representational or non-representational interpretations of the Free Energy Principle are discussed. We also discuss how the Free Energy Principle may be seen as a unified view where terms that traditionally belong to different ontologies—e.g., notions of model and expectation versus notions of autopoiesis and synchronization—can be harmonized. However, rather than attempting to settle the representationalist versus non-representationalist debate and reveal something about what representations are *simpliciter*, this paper demonstrates how the Free Energy Principle may be used to reveal something about those partaking in the debate; namely, what *our* hidden assumptions about what representations are—assumptions that act as sometimes antithetical starting points in this persistent philosophical debate.

Necessitarianism and Dispositions

2021年4月12日 星期一 下午2:34 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Gozzano, Simone (2020) Necessitarianism and Dispositions. [Preprint]

Quantum Gravity and Mereology: Not So Simple

2021年4月12日 星期一 下午2:31 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Baron, Samuel and Le Bihan, Baptiste (2021) Quantum Gravity and Mereology: Not So Simple. [Preprint]

Measurement of the proton spin structure at long distances

2021年4月12日 星期一 上午8:00 | | | Z. W. Zhao | | | Nature Physics – Issue – nature.com science feeds |

Nature Physics, Published online: 12 April 2021; doi:10.1038/s41567-021-01198-z

Measurements of the proton’s spin structure in experiments scattering a polarized electron beam off polarized protons in regions of low momentum transfer squared test predictions from chiral effective field theory of the strong interaction.

Physicalism without the idols of mathematics

2021年4月12日 星期一 上午6:48 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Szabo, Laszlo E. (2021) Physicalism without the idols of mathematics. [Preprint]

]]>I comment briefly on derivations of the Born rule presented by Masanes et al. and by Hossenfelder.

]]>This is a reply to Silberstein’s review of my book “Einstein’s Unfinished Revolution”.

]]>2021年4月10日 星期六 上午2:33 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Park, Seungbae (2021) Quantum Entanglement Undermines Structural Realism. Metaphysica.

How Artworks Modify our Perception of the World

2021年4月10日 星期六 上午2:32 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Vernazzani, Alfredo (2021) How Artworks Modify our Perception of the World. [Preprint]

Geometry of Faithful Entanglement

2021年4月9日 星期五 下午6:00 | | | Otfried Gühne, Yuanyuan Mao, and Xiao-Dong Yu | | | PRL: General Physics: Statistical and Quantum Mechanics, Quantum Information, etc. |

Author(s): Otfried Gühne, Yuanyuan Mao, and Xiao-Dong Yu

A typical concept in quantum state analysis is based on the idea that states in the vicinity of some pure entangled state share the same properties, implying that states with a high fidelity must be entangled. States whose entanglement can be detected in this way are also called faithful. We prove a…

[Phys. Rev. Lett. 126, 140503] Published Fri Apr 09, 2021

Detecting Many-Body Bell Nonlocality by Solving Ising Models

2021年4月9日 星期五 下午6:00 | | | Irénée Frérot and Tommaso Roscilde | | | PRL: General Physics: Statistical and Quantum Mechanics, Quantum Information, etc. |

Author(s): Irénée Frérot and Tommaso Roscilde

Bell nonlocality represents the ultimate consequence of quantum entanglement, fundamentally undermining the classical tenet that spatially separated degrees of freedom possess objective attributes independently of the act of their measurement. Despite its importance, probing Bell nonlocality in many…

[Phys. Rev. Lett. 126, 140504] Published Fri Apr 09, 2021

A tale of two kinds of exceptional point in a hydrogen molecule. (arXiv:2104.03383v1 [quant-ph])

2021年4月9日 星期五 下午5:43 | | | Himadri Barman, Suriyaa Valliapan | | | quant-ph updates on arXiv.org |

We study the parity and time-reversal ($\mathcal{PT}$) symmetric quantum physics in a non-Hermitian non-relativistic hydrogen molecule with local (Hubbard type) Coulomb interaction. We consider non-Hermiticity generated from both kinetic and orbital energies of the atoms and encounter the existence of two different types of exceptional points (EPs) in pairs. These two kinds of EP are characteristically different and depend differently on the interaction strength. Our discovery may open the gates of a rich physics emerging out of a simple Hamiltonian resembling a two-site Hubbard model.

Do Bloch waves interfere with one another ?. (arXiv:2104.03622v1 [quant-ph])

2021年4月9日 星期五 下午5:43 | | | Vivek M. Vyas | | | quant-ph updates on arXiv.org |

Here we show that two Bloch states, which are energy eigenstates of a quantum periodic potential problem, with different wavevectors can not be linearly superposed to display quantum interference of any kind that captures the relative phase between them. This is due to the existence of a superselection rule in these systems, whose origin lies in the discrete translation symmetry. A topological reason leading to such a superselection is found. A temporal analogue of this superselection rule in periodically driven quantum systems is also uncovered, which forbids the coherent superposition of any two quasi-periodic Floquet states with different quasienergies.

2021年4月9日 星期五 下午5:43 | | | Giuseppe Bimonte, Benjamin Spreng, Paulo A. Maia Neto, Gert-Ludwig Ingold, Galina L. Klimchitskaya, Vladimir M. Mostepanenko, Ricardo S. Decca | | | quant-ph updates on arXiv.org |

We present results on the determination of the differential Casimir force between an Au-coated sapphire sphere and the top and bottom of Au-coated deep silicon trenches performed by means of the micromechanical torsional oscillator in the range of separations from 0.2 to 8 $\upmu$m. The random and systematic errors in the measured force signal are determined at the 95\% confidence level and combined into the total experimental error. The role of surface roughness and edge effects is investigated and shown to be negligibly small. The distribution of patch potentials is characterized by Kelvin probe microscopy, yielding an estimate of the typical size of patches, the respective r.m.s. voltage and their impact on the measured force. A comparison between the experimental results and theory is performed with no fitting parameters. For this purpose, the Casimir force in the sphere-plate geometry is computed independently on the basis of first principles of quantum electrodynamics using the scattering theory and the gradient expansion. In doing so, the frequency-dependent dielectric permittivity of Au is found from the optical data extrapolated to zero frequency by means of the plasma and Drude models. It is shown that the measurement results exclude the Drude model extrapolation over the region of separations from 0.2 to 4.8~$\upmu$m, whereas the alternative extrapolation by means of the plasma model is experimentally consistent over the entire measurement range. A discussion of the obtained results is provided.

Quantum Zeno effect generalized. (arXiv:1901.09393v3 [math-ph] UPDATED)

2021年4月9日 星期五 下午5:43 | | | Tim Möbus, Michael M. Wolf | | | quant-ph updates on arXiv.org |

The quantum Zeno effect, in its original form, uses frequent projective measurements to freeze the evolution of a quantum system that is initially governed by a fixed Hamiltonian. We generalize this effect simultaneously in three directions by allowing open system dynamics, time-dependent evolution equations and general quantum operations in place of projective measurements. More precisely, we study Markovian master equations with bounded generators whose time dependence is Lipschitz continuous. Under a spectral gap condition on the quantum operation, we show how frequent measurements again freeze the evolution outside an invariant subspace. Inside this space the evolution is described by a modified master equation.

Fluctuation theorems from Bayesian retrodiction. (arXiv:2009.02849v4 [quant-ph] UPDATED)

2021年4月9日 星期五 下午5:43 | | | Francesco Buscemi, Valerio Scarani | | | quant-ph updates on arXiv.org |

Quantitative studies of irreversibility in statistical mechanics often involve the consideration of a reverse process, whose definition has been the object of many discussions, in particular for quantum mechanical systems. Here we show that the reverse channel very naturally arises from Bayesian retrodiction, both in classical and quantum theories. Previous paradigmatic results, such as Jarzynski’s equality, Crooks’ fluctuation theorem, and Tasaki’s two-measurement fluctuation theorem for closed driven quantum systems, are all shown to be consistent with retrodictive arguments. Also, various corrections that were introduced to deal with nonequilibrium steady states or open quantum systems are justified on general grounds as remnants of Bayesian retrodiction. More generally, with the reverse process constructed on consistent logical inference, fluctuation relations acquire a much broader form and scope.

2021年4月9日 星期五 下午5:43 | | | physics.hist-ph updates on arXiv.org |

Authors: Geraint F. Lewis, Luke A. Barnes

Are some cosmologists trying to return human beings to the centre of the cosmos? In the view of some critics, the so-called “anthropic principle” is a desperate attempt to salvage a scrap of dignity for our species after a few centuries of demotion at the hands of science. It is all things archaic and backwards – teleology, theology, religion, anthropocentrism – trying to sneak back in scientific camouflage. We argue that this is a mistake. The anthropic principle is not mere human arrogance, nor is it religion in disguise. It is a necessary part of the science of the universe.

The Autodidactic Universe. (arXiv:2104.03902v1 [hep-th])

2021年4月9日 星期五 下午5:43 | | | physics.hist-ph updates on arXiv.org |

Authors: Stephon Alexander, William J. Cunningham, Jaron Lanier, Lee Smolin, Stefan Stanojevic, Michael W. Toomey, Dave Wecker

We present an approach to cosmology in which the Universe learns its own physical laws. It does so by exploring a landscape of possible laws, which we express as a certain class of matrix models. We discover maps that put each of these matrix models in correspondence with both a gauge/gravity theory and a mathematical model of a learning machine, such as a deep recurrent, cyclic neural network. This establishes a correspondence between each solution of the physical theory and a run of a neural network. This correspondence is not an equivalence, partly because gauge theories emerge from $N \rightarrow \infty $ limits of the matrix models, whereas the same limits of the neural networks used here are not well-defined. We discuss in detail what it means to say that learning takes place in autodidactic systems, where there is no supervision. We propose that if the neural network model can be said to learn without supervision, the same can be said for the corresponding physical theory. We consider other protocols for autodidactic physical systems, such as optimization of graph variety, subset-replication using self-attention and look-ahead, geometrogenesis guided by reinforcement learning, structural learning using renormalization group techniques, and extensions. These protocols together provide a number of directions in which to explore the origin of physical laws based on putting machine learning architectures in correspondence with physical theories.

Machine-Learning Mathematical Structures. (arXiv:2101.06317v2 [cs.LG] UPDATED)

2021年4月9日 星期五 下午5:43 | | | physics.hist-ph updates on arXiv.org |

Authors: Yang-Hui He

We review, for a general audience, a variety of recent experiments on extracting structure from machine-learning mathematical data that have been compiled over the years. Focusing on supervised machine-learning on labeled data from different fields ranging from geometry to representation theory, from combinatorics to number theory, we present a comparative study of the accuracies on different problems. The paradigm should be useful for conjecture formulation, finding more efficient methods of computation, as well as probing into certain hierarchy of structures in mathematics.

Statistical mechanics of systems with negative temperature

2021年4月9日 星期五 下午5:43 | | | ScienceDirect Publication: Physics ReportsScienceDirect RSShttps://www.sciencedirect.com/journal/physics-reportsRSS for NodeTue, 23 Jul 2019 10:02:48 GMTCopyright © 2019 Elsevier B.V. All rights reservedRapid solidification as non-ergodic phenomenonPublication date: 20 July 2019Source: Physics Reports, Volume 818Author(s): P.K. Galenko, D. JouAbstractRapid solidification is a relevant physical phenomenon in material sciences, whose theoretical analysis requires going beyond the limits of local equilibrium statistical physics and thermodynamics and, in particular, taking account of ergodicity breaking and of generalized formulation of thermodynamics. The ergodicity breaking is related to the time symmetry breaking and to the presence of some kinds of fluxes and gradient flows making that an average of microscopic variables along time is different than an average over some chosen statistical ensemble. In fast processes, this is due, for instance, to the fact that the system has no time enough to explore the who |

Publication date: Available online 5 April 2021

**Source:** Physics Reports

Author(s): Marco Baldovin, Stefano Iubini, Roberto Livi, Angelo Vulpiani

Probing new physics for $(g-2)_\mu$ and gravitational waves. (arXiv:2104.03519v1 [hep-ph])

2021年4月9日 星期五 下午5:43 | | | gr-qc updates on arXiv.org |

Authors: Ruiyu Zhou, Ligong Bian, Jing Shu

We study the possibility of probing new physics accounting for $(g-2)_\mu$ anomaly and gravitational waves with pulsar timing array measurements. The model we consider is either a light gauge boson or neutral scalar interacting with muons. We show that the parameter spaces of dark $U(1)$ model with kinetic mixing explaining $(g-2)_\mu$ anomaly can realize a first-order phase transition, and the yield-produced gravitational wave may address the common red noise observed in the NANOGrav 12.5-yr dataset.

Canonical structure of minimal varying $\Lambda$ theories. (arXiv:2104.03753v1 [gr-qc])

2021年4月9日 星期五 下午5:43 | | | gr-qc updates on arXiv.org |

Authors: Sergei Alexandrov, Simone Speziale, Tom Zlosnik

Minimal varying $\Lambda$ theories are defined by an action built from the Einstein-Cartan-Holst first order action for gravity with the cosmological constant $\Lambda$ as an independent scalar field, and supplemented by the Euler and Pontryagin densities multiplied by $1/\Lambda$. We identify the canonical structure of these theories which turn out to represent an example of irregular systems. We find five degrees of freedom on generic backgrounds and for generic values of parameters, whereas if the parameters satisfy a certain condition (which includes the most commonly considered Euler case) only three degrees of freedom remain. On de Sitter-like backgrounds the canonical structure changes, and due to an emergent conformal symmetry one degree of freedom drops from the spectrum. We also analyze the self-dual case with an holomorphic action depending only on the self-dual part of the connection. In this case we find two (complex) degrees of freedom, and further discuss the Kodama state, the restriction to de Sitter background and the effect of reality conditions.

2021年4月9日 星期五 下午5:43 | | | gr-qc updates on arXiv.org |

Authors: B. Wojtsekhowski, Dmitry Budker

High-precision tests of local Lorentz invariance, via monitoring of the sidereal time variation of the photon energies emitted by ultrarelativistic heavy-ion beams and of the beam momentum, are proposed. This paper includes descriptions of the physics ideas and the concept for the detector. The experiment results will allow high-precision tests of LLI via anisotropy of the maximum attainable speed of a photon and an ion. The projected accuracy for the asymmetries interpreted in the framework of the anisotropic relativistic mechanics corresponds to the limit on sidereal time variation of the one-way maximum attainable speed at the levels between $10^{-14}$ and $10^{-17}$.

Possible existence of time machines in a five-dimensional spacetime. (arXiv:2104.03790v1 [gr-qc])

2021年4月9日 星期五 下午5:43 | | | gr-qc updates on arXiv.org |

Authors: Peter K.F. Kuhfittig

The idea of constructing a time machine is not new and even received a boost thanks to the realization that a traversable wormhole could be converted to a time machine. This also implied that it would be impossible to travel back in time beyond the creation of the time machine. This paper addresses these issues, as well as the concomitant causality violations, by starting with a physically acceptable model, a spacetime that is anti-de Sitter due to an extra time-like dimension, thereby allowing the existence of closed time-like curves. By assuming that the extra dimension is independent of the radial coordinate, the wormhole retains its basic geometric properties regardless of its location and can therefore serve as a shortcut for any closed time-like curve, which, in turn, can extend indefinitely into the past. The same independence of the radial coordinate suggests that the wormhole could connect a region in the present to a local region that (1) lies in the past and (2) does not contain any closed time-like curves. Previous studies have suggested that if such a region is sufficiently localized, it may be possible to avoid a causality violation.

$T\bar T$ deformation on multi-quantum mechanics and regenesis. (arXiv:2104.03852v1 [hep-th])

2021年4月9日 星期五 下午5:43 | | | gr-qc updates on arXiv.org |

Authors: Sone He, Zhuo-Yu Xian

We study the $T\bar T$ deformation on a multi-quantum mechanical systems. By introducing the dynamical coordinate transformation, we obtain the deformed theory as well as the solution. We further study the thermo-field-double state under the $T\bar T$ deformation on these systems, including conformal quantum mechanical system, the Sachdev-Ye-Kitaev model, and the model satisfying Eigenstate Thermalization Hypothesis. We find common regenesis phenomena where the signal injected into one local system can regenerate from the other local system. From the bulk picture, we study the deformation on Jackiw-Teitelboim gravity governed by Schwarzian action and find that the regenesis phenomena here are not related to the causal structure of semi-classical wormhole.

2021年4月9日 星期五 上午8:00 | | | Abigail Klopper | | | Nature Physics – Issue – nature.com science feeds |

Nature Physics, Published online: 09 April 2021; doi:10.1038/s41567-021-01228-w

Nerve rays on the brain

One outstanding path from A to B

2021年4月9日 星期五 上午8:00 | | | Samuel V. Scarpino | | | Nature Physics – Issue – nature.com science feeds |

Nature Physics, Published online: 09 April 2021; doi:10.1038/s41567-021-01222-2

What does it mean for an individual to be ‘important’ or for a connection to be ‘outstanding’? The answer depends on context, as Sarah Shugars and Samuel V. Scarpino explain.

Phenomenal Roles: A Dispositional Account of Bodily Pain

2021年4月5日 星期一 上午1:15 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Gozzano, Simone (2021) Phenomenal Roles: A Dispositional Account of Bodily Pain. [Preprint]

2021年4月5日 星期一 上午1:13 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Kubiak, Adam P. (2021) Applying Perspectival Realism to Frequentist Statistics: The Case of Jerzy Neyman’s Methodology and Philosophy. In: UNSPECIFIED.

Testing Quantum Mechanics with an Ultra-Cold Particle Trap

by Peter J. Riggs

It is possible to empirically discriminate between the predictions of orthodox (i.e., Copenhagen) quantum theory and the de Broglie−Bohm theory of quantum mechanics. A practical experiment is proposed in which a single, laser-cooled ion inside an ultra-cold particle trap is either found to be near the trap’s walls or not. Detections of the former kind would support the prediction of orthodox quantum theory and of the latter kind would support the de Broglie−Bohm theory. The outcome of this experiment would show which theory gives the more correct description and, consequently, would have far-reaching implications for our understanding of quantum mechanics. View Full-Text

]]>上午2:21 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Pruss, Dasha (2021) Mechanical Jurisprudence and Domain Distortion: How Predictive Algorithms Warp the Law. [Preprint]

Approaching probabilistic and deterministic nomic truths in an inductive probabilistic way

上午2:21 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Kuipers, Theo A.F. (2021) Approaching probabilistic and deterministic nomic truths in an inductive probabilistic way. [Preprint]

The Philosophy of the Future of Science

上午2:16 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Virmajoki, Veli (2021) The Philosophy of the Future of Science. [Preprint]

What Theoretical Equivalence Could Not Be

上午2:12 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Teitel, Trevor (2021) What Theoretical Equivalence Could Not Be. [Preprint]

Physics and Metaphysics of Wigner’s Friends: Even Performed Premeasurements Have No Results

2021年4月2日 星期五 下午6:00 | | | Marek Żukowski and Marcin Markiewicz | | | PRL: General Physics: Statistical and Quantum Mechanics, Quantum Information, etc. |

Author(s): Marek Żukowski and Marcin Markiewicz

“The unambiguous account of proper quantum phenomena must, in principle, include a description of all relevant features of experimental arrangement” (Bohr). The measurement process is composed of premeasurement (quantum correlation of the system with the pointer variable) and an irreversible decoher…

[Phys. Rev. Lett. 126, 130402] Published Fri Apr 02, 2021

2021年4月2日 星期五 上午10:12 | | | H. Moaiery, A. Chenani, A. Hakimifard, N. Tahmasebi | | | quant-ph updates on arXiv.org |

In this work, the general form of $2\times2$ Dirac matrices for 2+1 dimension is found. In order to find this general representation, all relations among the elements of the matrices and matrices themselves are found,and the generalized Lorentz transform matrix is also found under the effect of the general representation of Dirac matrices. As we know, the well known equation of Dirac, $ \left( i\gamma^{\mu}\partial_{\mu}-m\right) \Psi=0 $, is consist of matrices of even dimension known as the general representation of Dirac matrices or Dirac matrices. Our motivation for this study was lack of the general representation of these matrices despite the fact that more than nine decades have been passed since the discovery of this well known equation. Everyone has used a specific representation of this equation according to their need; such as the standard representation known as Dirac-Pauli Representation, Weyl Representation or Majorana representation. In this work, the general form which these matrices can have is found once for all.

Why is AI hard and Physics simple?. (arXiv:2104.00008v1 [cs.LG])

2021年4月2日 星期五 上午10:12 | | | physics.hist-ph updates on arXiv.org |

Authors: Daniel A. Roberts

We discuss why AI is hard and why physics is simple. We discuss how physical intuition and the approach of theoretical physics can be brought to bear on the field of artificial intelligence and specifically machine learning. We suggest that the underlying project of machine learning and the underlying project of physics are strongly coupled through the principle of sparsity, and we call upon theoretical physicists to work on AI as physicists. As a first step in that direction, we discuss an upcoming book on the principles of deep learning theory that attempts to realize this approach.

Time Symmetry in Operational Theories. (arXiv:2104.00071v1 [quant-ph])

2021年4月2日 星期五 上午10:12 | | | gr-qc updates on arXiv.org |

Authors: Lucien Hardy

The standard operational probabilistic framework (within which we can formulate Operational Quantum Theory) is time asymmetric. This is clear because the conditions on allowed operations are time asymmetric. It is odd, though, because Schoedinger’s equation is time symmetric and probability theory does not care about time direction. In this work we provide a time symmetric framework for operational theories in general and for Quantum Theory in particular.

The clearest expression of the time asymmetry of standard Operational Quantum Theory is that the deterministic effect is unique – meaning there is only one way to ignore the future – while deterministic (i.e normalised) states are not unique. In this paper, this time asymmetry is traced back to a time asymmetric understanding of the most basic elements of an operational theory – namely the operations (or boxes) out of which circuits are built. We modify this allowing operations to have classical incomes as well as classical outcomes on these operations. We establish a time symmetric operational framework for circuits built out of operations. In particular, we demand that the probability associated with a circuit is the same whether we calculate it forwards in time or backwards in time. We do this by imposing various double properties. These are properties wherein a forward in time and a backward in time version of the same property are required. In this paper we provide a new causality condition which we call double causality.

The topological order of the space. (arXiv:2104.00227v1 [gr-qc])

2021年4月2日 星期五 上午10:12 | | | gr-qc updates on arXiv.org |

Authors: Jingbo Wang

Topological order is a new type order that beyond Landau’s symmetry breaking theory. The topological entanglement entropy provides a universal quantum number to characterize the topological order in a system. The topological entanglement entropy of the BTZ black hole was calculated and found that it coincides with that for fractional quantum Hall state. So the BTZ black holes have the same topological order with the fractional quantum Hall state. We conjecture that black holes in higher dimensions also have topological orders. Next we want to study the topological order of ordinary spaces which can be described by spin network states in loop quantum gravity. We advise to bring in the methods and results in string-net condensation to loop quantum gravity to solve some difficult problems.

A peek outside our Universe. (arXiv:2104.00521v1 [gr-qc])

2021年4月2日 星期五 上午10:12 | | | gr-qc updates on arXiv.org |

Authors: Enrique Gaztanaga, Pablo Fosalba

According to General Relativity (GR) a universe with a cosmological constant, Lambda, like ours, is trapped inside an event horizon r< sqrt(3/Lambda). What is outside? We show, using Israel (1967) junction conditions, that there could be a different universe outside. Our Universe looks like a Black Hole for an outside observer. Outgoing radial null geodesics can not escape our universe, but incoming photons can enter and leave an imprint on our CMB sky. We present a picture of such a fossil record from the analysis of CMB maps that agrees with the Black Hole universe predictions but challenge our understanding of the origin of the primordial universe.

Quantum Measurement of Space-Time Events. (arXiv:2011.11541v3 [quant-ph] UPDATED)

2021年4月2日 星期五 上午10:12 | | | gr-qc updates on arXiv.org |

Authors: Dorje C. Brody, Lane P. Hughston

The phase space of a relativistic system can be identified with the future tube of complexified Minkowski space. As well as a complex structure and a symplectic structure, the future tube, seen as an eight-dimensional real manifold, is endowed with a natural positive-definite Riemannian metric that accommodates the underlying geometry of the indefinite Minkowski space metric, together with its symmetry group. A unitary representation of the 15-parameter group of conformal transformations can then be constructed that acts upon the Hilbert space of square-integrable holomorphic functions on the future tube. These structures are enough to allow one to put forward a quantum theory of phase-space events. In particular, a theory of quantum measurement can be formulated in a relativistic setting, based on the use of positive operator valued measures, for the detection of phase-space events, hence allowing one to assign probabilities to the outcomes of joint space-time and four-momentum measurements in a manifestly covariant framework. This leads to a localization theorem for phase-space events in relativistic quantum theory, determined by the associated Compton wavelength.

Maxwellian mirages in general relativity. (arXiv:2012.08077v2 [gr-qc] UPDATED)

2021年4月2日 星期五 上午10:12 | | | gr-qc updates on arXiv.org |

Authors: L.L. Williams, N. Inan

Maxwellian approximations to linear general relativity are revisited in light of relatively recent results on the degrees of freedom in the linear gravitational field. The well-known Maxwellian formalism obtained in harmonic coordinates is compared with a Maxwellian formalism obtained under a coordinate choice where each of the metric components corresponds to each of the coordinate-invariant degrees of freedom of the linear gravitational field. The coordinate freedom of general relativity can be exploited to cast the field equations into Maxwellian form, but such forms can be mere mirages of the coordinate choice — mirages such as vector gravitational waves. A coordinate choice that yields perfectly-Maxwellian field equations, will yield a force equation that is not Lorentzian. If field definitions are chosen to obtain Lorentz-like terms in the force equation, then Maxwellian forms are compromised in the field equations. Many treatments of gravito-electromagnetism will make inconsistent ordering choices between the field equations and force equations, or else truncate terms of relevant order from the force equation. Often such mistakes reflect an attempt to force exact Maxwellian analogs simultaneously in both the field equations and the force equation, with the result that terms dropped are as large as those kept.

2021年4月2日 星期五 上午8:00 | | | Jan Ryckebusch | | | Nature Physics – Issue – nature.com science feeds |

Nature Physics, Published online: 02 April 2021; doi:10.1038/s41567-021-01224-0

A detailed analysis of a nucleon-knockout experiment has put forward a methodological roadmap for overcoming ambiguities in the interpretation of the data — promising access to the nuclear wave functions in unstable nuclei.

2021年4月1日 星期四 上午8:00 | | | Arianna Bottinelli | | | Nature Physics – Issue – nature.com science feeds |

Nature Physics, Published online: 01 April 2021; doi:10.1038/s41567-021-01220-4

Unreal art and hidden physics

Mind-body interaction and modern physics

2021年4月1日 星期四 上午2:39 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Anastopoulos, Charis (2020) Mind-body interaction and modern physics. [Preprint]

Noether’s Theorems and Energy in General Relativity

2021年4月1日 星期四 上午2:36 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

De Haro, Sebastian (2021) Noether’s Theorems and Energy in General Relativity. [Preprint]

QBism and the Limits of Scientific Realism

2021年3月30日 星期二 下午1:11 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Glick, David (2021) QBism and the Limits of Scientific Realism. [Preprint]

2021年3月28日 星期日 上午3:50 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Vessonen, Elina (2021) Representation in Measurement. [Preprint]

Were EPR correct after all; did Bell miss a point

2021年3月28日 星期日 上午3:49 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Thompson, John F (2021) Were EPR correct after all; did Bell miss a point. UNSPECIFIED.

]]>The circles theory tries to explain the complex functioning of the harmonic oscillator. It is a non-quantum mechanics theory, but it shows a good similarity with the forms of equations of the relativistic quantum mechanics. The Circles Theory explains the association of the wave and the point that corresponds with the wave and particle of quantum mechanics. According to the circular motions of an individual system, a fluid model for a huge number of the circular system is expected to be formed. Then, a wave of fluid may appear. So, a real wave of fluid-type is seen due to the circular motion in addition to the wave associated with the point or the particle. In this article, the double slit experiment has been explained in accordance with the circles theory. According to the circles theory, the double slit experiment shows that this fluid-like wave is responsible for the interference pattern, whereas the associate wave is responsible for the uncertain location of the particle on the screen. On the other hand, the observation of the fluid may destroy the formulation of the wave of fluid. If this happens, then the interference disappears, but a pattern of shout bullets appears. The rolling circles model of the circles theory cannot be investigated excrementally. This explanation of the double slit experiment may prove the existence of this rolling circles system.

]]>The quantum measurement problem is the most fundamental question of all: How the ghostly quantum mechanical coexistence of many mutually incompatible possibilities result in the concrete reality of the normal world, even though we and our measuring instruments are all made of atoms obeying quantum mechanics. In this brief article we lay down the criteria for such a mechanism.

]]>By treating an electron as its own Electromagnetic (EM) field and generalizing the Lorentz force to be the field force between the electron’s EM field and its external EM field, it is proved that the radiating field and the Coulomb-like field of an accelerated electron do interact, with the radiating field provides the exact momentum change needed by the Coulomb-like field. Thus, the radiating field of an accelerated electron fulfills the role of virtual photon in Quantum Electrodynamics (QED). By treating the radiating field as virtual photon, it is closely examined how the virtual photon is emitted and absorbed by the electron, and how the condition which leads to infinity in QED can be removed. Consequently, the necessity of Renormalization is removed. The conventional formula of the radiation power by an accelerated electron is questioned, and a new formula is given. Two experiments to test the new formula are proposed. When the electron is treated as its own EM field and its location is the center of mass of its EM field, it is explained why an electron does not radiate when it free-falls under the gravity.

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