# Weekly Papers on Quantum Foundations (5)

Temporal binding: digging into animal minds through time perception

Abstract

Temporal binding is the phenomenon in which events related as cause and effect are perceived by humans to be closer in time than they actually are (Haggard et al. in Nat Neurosci 5(4):382–385, 2002, https://doi.org/10.1038/nn827). Despite the fact that temporal binding experiments with humans have relied on verbal instructions, we argue that they are adaptable to nonhuman animals, and that a finding of temporal binding from such experiments would provide evidence of causal reasoning that cannot be reduced to associative learning. Our argument depends on describing and theoretically motivating an intermediate level of representations between the lower levels of associations of sensory features and higher symbolic representations. This intermediate level of representations makes it possible to challenge arguments given by some comparative psychologists that animals lack higher-level abstract and explicit forms of causal reasoning because their cognitive capacities are limited to learning and reasoning at the basic level of perceptual associations. Our multi-level account connects time perception with causal reasoning and provides a philosophically defensible framework for experimental investigations that have not yet been pursued. We describe the structure of some possible experiments and consider the implications that would follow from a positive finding of temporal binding in nonhuman animals. Such a finding would provide evidence of explicit awareness of causal relationships and would warrant attribution of intermediate representations that are more abstract and sophisticated than the associations allowed by the lower level of the two-level account.

The Universe as a Quantum Encoder. (arXiv:2201.11658v1 [hep-th])

Quantum mechanical unitarity in our universe is challenged both by the notion of the big bang, in which nothing transforms into something, and the expansion of space, in which something transforms into more something. This motivates the hypothesis that quantum mechanical time evolution is always isometric, in the sense of preserving inner products, but not necessarily unitary. As evidence for this hypothesis we show that in two spacetime dimensions (i) there is net entanglement entropy produced in free field theory by a moving mirror or expanding geometry, (ii) the Lorentzian path integral for a finite elements lattice discretization gives non-unitary isometric time evolution, and (iii) tensor network descriptions of AdS$_3$ induce a non-unitary but isometric time evolution on an embedded two-dimensional de Sitter braneworld. In the last example time evolution is a quantum error-correcting code.

Full network nonlocality. (arXiv:2105.09325v2 [quant-ph] UPDATED)

Networks have advanced the study of nonlocality beyond Bell’s theorem. Here, we introduce the concept of full network nonlocality, which describes correlations that necessitate all links in a network to distribute nonlocal resources. Showcasing that this notion is stronger than standard network nonlocality, we prove that the most well-known network Bell test does not witness full network nonlocality. In contrast, we demonstrate that its generalisation to star networks is capable of detecting full network nonlocality in quantum theory. More generally, we point out that established methods for analysing local and theory-independent correlations in networks can be combined in order to systematically deduce sufficient conditions for full network nonlocality in any network and input/output scenario. We demonstrate the usefulness of these methods by constructing polynomial witnesses of full network nonlocality for the bilocal scenario. Then, we show that these inequalities can be violated via quantum Elegant Joint Measurements.

Hilbert space fragmentation produces a “fracton Casimir effect”. (arXiv:2105.11465v2 [quant-ph] UPDATED)

Fracton systems exhibit restricted mobility of their excitations due to the presence of higher-order conservation laws. Here we study the time evolution of a one-dimensional fracton system with charge and dipole moment conservation using a random unitary circuit description. Previous work has shown that when the random unitary operators act on four or more sites, an arbitrary initial state eventually thermalizes via a universal subdiffusive dynamics. In contrast, a system evolving under three-site gates fails to thermalize due to strong “fragmentation” of the Hilbert space. Here we show that three-site gate dynamics causes a given initial state to evolve toward a highly nonthermal state on a time scale consistent with Brownian diffusion. Strikingly, the dynamics produces an effective attraction between isolated fractons or between a single fracton and the boundaries of the system, in analogy with the Casimir effect in quantum electrodynamics. We show how this attraction can be understood by exact mapping to a simple classical statistical mechanics problem, which we solve exactly for the case of an initial state with either one or two fractons.

A Simple Proof of Locality in Quantum Mechanics. (arXiv:2108.10694v3 [physics.gen-ph] UPDATED)

While quantum mechanics allows spooky action at a distance at the level of the wave-function, it also respects locality since there is no instantaneous propagation of real physical effects. We show that this feature can be proved in the standard interpretation of quantum mechanics by a simple general result involving commuting Hermitian operators corresponding to distant (causally disconnected) observables. This is reminiscent of satisfying the locality condition in relativistic quantum field theories.

Singularities From Entropy. (arXiv:2201.11132v1 [hep-th])

Assuming the Bousso bound, we prove a singularity theorem: if the light rays entering a hyperentropic region contract, then at least one light ray must be incomplete. “Hyperentropic” means that the entropy of the region exceeds the Bekenstein-Hawking entropy of its spatial boundary. Our theorem provides a direct link between singularities and quantum information. The hyperentropic condition replaces the noncompactness assumption in Penrose’s theorem, so our theorem is applicable even in a closed universe. In an asymptotically de Sitter spacetime, for example, a big bang singularity can be diagnosed from the presence of dilute radiation at arbitrarily late times. In asymptotically flat space, Penrose’s theorem can be recovered by adding soft radiation.

Varying Coupling Constants and Their Interdependence. (arXiv:2201.11667v1 [gr-qc])

Authors: Rajendra P Gupta

Since Dirac predicted in 1937 possible variation of gravitational constant and other coupling constants from his large number hypothesis, efforts continue to determine such variation without success. Such efforts focus on the variation of one constant while assuming all others pegged to their currently measured values. We show that the variations of the Boltzmann constant $k$, the speed of light $c$, the gravitational constant $G$, and the Planck constant $h$ are interrelated: $G\thicksim c^{3}\thicksim h^{3}\thicksim k^{3/2}$. Thus, constraining any one of the constants leads to inadvertently constraining all the others. It may not be possible to determine the variation of a constant without concurrently considering the variation of others.

Is the Hubble crisis connected with the extinction of dinosaurs?. (arXiv:2201.08997v2 [astro-ph.EP] UPDATED)

Authors: Leandros Perivolaropoulos

It has recently been suggested that a gravitational transition of the effective Newton’s constant $G_{\rm eff}$ by about 10%, taking place 50-150 Myrs ago, can lead to the resolution of both the Hubble crisis and the growth tension of the standard $\Lambda$CDM model. Hints for such an abrupt transition with weaker gravity at times before the transition, have recently been identified in Tully Fisher galactic mass-velocity data and also in Cepheid SnIa calibrator data. Here we use Monte-Carlo simulations to show that such a transition could significantly increase (by a factor of 3 or more) the number of long period comets (LPCs) impacting the solar system from the Oort cloud (semi-major axis of orbits $\gtrsim 10^4AU$). This increase is consistent with observational evidence from the terrestrial and lunar cratering rates indicating that the impact flux of kilometer sized objects increased by at least a factor of 2 over that last 100 Myrs compared to the long term average. This increase may also be connected with the Chicxulub impactor event that produced the Cretaceous-Tertiary (K-T) extinction of 75% of life on Earth (including dinosaurs) about 66 Myrs ago. We use Monte-Carlo simulations to show that for isotropic Oort cloud comet distribution with initially circular orbits, random velocity perturbations (induced eg by passing stars and/or galactic tidal effects), lead to a deformation of the orbits that increases significantly when $G_{\rm eff}$ increases. A 10% increase of $G_{\rm eff}$ leads to an increase in the probability of the comets to enter the loss cone and reach the planetary region (pericenter of less than 10AU) by a factor that ranges from 5% (for velocity perturbation much smaller than the comet initial velocity) to more than 300% (for total velocity perturbations comparable with the initial comet velocity).

Topological Explanations: An Opinionated Appraisal

Kostic, Daniel (2021) Topological Explanations: An Opinionated Appraisal. [Preprint]

Relational event-time in quantum mechanics

Fortin, Sebastian and Lombardi, Olimpia and Pasqualini, Matias (2021) Relational event-time in quantum mechanics. Foundations of Physics, 52. p. 10. ISSN 0015-9018

Many Worlds are irrelevant for the problem of the arrow of time

Baumann, Veronika and Del Santo, Flavio (2022) Many Worlds are irrelevant for the problem of the arrow of time. [Preprint]

Entanglement and indistinguishability in a quantum ontology of properties

Fortin, Sebastian and Lombardi, Olimpia (2021) Entanglement and indistinguishability in a quantum ontology of properties. [Preprint]

Spacetime Quietism in Quantum Gravity

Baron, Samuel and Le Bihan, Baptiste (2022) Spacetime Quietism in Quantum Gravity. [Preprint]

Back to Reichenbach

ROVELLI, Carlo (2022) Back to Reichenbach. [Preprint]

Causal Explanation in Physics

Frisch, Mathias (2022) Causal Explanation in Physics. [Preprint]

The Babylonian conception and conventionalism about laws in physics

Frisch, Mathias (2022) The Babylonian conception and conventionalism about laws in physics. [Preprint]

Heisenberg-Limited Metrology via Weak-Value Amplification without Using Entangled Resources

Author(s): Yosep Kim, Seung-Yeun Yoo, and Yoon-Ho Kim

Weak-value amplification (WVA) provides a way for amplified detection of a tiny physical signal at the expense of a lower detection probability. Despite this trade-off, due to its robustness against certain types of noise, WVA has advantages over conventional measurements in precision metrology. Mor…

[Phys. Rev. Lett. 128, 040503] Published Tue Jan 25, 2022

Ruling Out Real-Valued Standard Formalism of Quantum Theory

Author(s): Ming-Cheng Chen, Can Wang, Feng-Ming Liu, Jian-Wen Wang, Chong Ying, Zhong-Xia Shang, Yulin Wu, M. Gong, H. Deng, F.-T. Liang, Qiang Zhang, Cheng-Zhi Peng, Xiaobo Zhu, Adán Cabello, Chao-Yang Lu, and Jian-Wei Pan

Studies demonstrate that a formulation of quantum mechanics involving complex rather than real numbers is necessary to reproduce experimental results.

[Phys. Rev. Lett. 128, 040403] Published Mon Jan 24, 2022

The Causal Structure of Reality

Papineau, David (2021) The Causal Structure of Reality. [Preprint]

Are We Free to Make the Laws?

Loew, Christian and Hüttemann, Andreas (2021) Are We Free to Make the Laws? [Preprint]

Can Schrodinger’s Cat Be Really a Quantum Touchstone?

Dumitru, Spiridon (2021) Can Schrodinger’s Cat Be Really a Quantum Touchstone? European Journal of Applied Physics, 3 (3). pp. 29-32. ISSN 2684-4451