from
by
Oliver H. E. Philcox
Fri Nov 03 2023 18:00:00 (14 hours)
# 1.
Author(s): Oliver H. E. Philcox
Observations of the cosmic microwave background (CMB) have cemented the notion that the large-scale Universe is both statistically homogeneous and isotropic. But is it invariant also under reflections? To probe this we require parity-sensitive statistics: for scalar observables, the simplest is the …
[Phys. Rev. Lett. 131, 181001] Published Fri Nov 03, 2023
Send To > Keep unreadDelete
from
by
José Manuel Agüero Trejo, Cristian S. Calude, Michael J. Dinneen, Arkady Fedorov, Anatoly Kulikov, Rohit Navarathna, Karl Svozil
Fri Nov 03 2023 17:49:33 (14 hours)
# 2.
A physical system is determined by a finite set of initial conditions and laws represented by equations. The system is computable if we can solve the equations in all instances using a “finite body of mathematical knowledge”. In this case, if the laws of the system can be coded into a computer program, then given the system’s initial conditions of the system, one can compute the system’s evolution. This scenario is tacitly taken for granted. But is this reasonable? The answer is negative, and a straightforward example is when the initial conditions or equations use irrational numbers, like Chaitin’s Omega Number: no program can deal with such numbers because of their “infinity”. Are there incomputable physical systems? This question has been theoretically studied in the last 30–40 years. This article presents a class of quantum protocols producing quantum random bits. Theoretically, we prove that every infinite sequence generated by these quantum protocols is strongly incomputable — no algorithm computing any bit of such a sequence can be proved correct. This theoretical result is not only more robust than the ones in the literature: experimental results support and complement it.
Send To > Keep unreadDelete
from
by
Zachary G. Lane, Antonia Seifert, Ryan Ridden-Harper, Jenny Wagner, David L. Wiltshire
Fri Nov 03 2023 17:49:26 (14 hours)
# 3.
We reanalyse the Pantheon+ supernova catalogue to compare a cosmology with non-FLRW evolution, the “timescape cosmology”, with the standard $\Lambda$CDM cosmology. To this end, we consider the Pantheon+ supernova catalogue, which is the largest available Type Ia supernova dataset for a geometric comparison between the two models. We construct a covariance matrix to be as independent of cosmology as possible, including independence from the FLRW geometry and peculiar velocity with respect to FLRW average evolution. Within this framework, which goes far beyond most other definitions of “model independence”, we introduce new statistics to refine Type Ia supernova (SneIa) light-curve analysis. In addition to conventional galaxy correlation functions used to define the scale of statistical homogeneity we introduce empirical statistics which enables a refined analysis of the distribution biases of SneIa light-curve parameters $\beta c$ and $\alpha x_1$.
For lower redshifts, the Bayesian analysis highlights important features attributable to the increased number of low-redshift supernovae, the artefacts of model-dependent light-curve fitting and the cosmic structure through which we observe supernovae. This indicates the need for cosmology-independent data reduction to conduct a stronger investigation of the emergence of statistical homogeneity and to compare alternative cosmologies in light of recent challenges to the standard model.
“Dark energy” is generally invoked as a place-holder for “new physics”. Our from-first-principles reanalysis of the Pantheon+ catalogue supports future deeper studies of the interplay of matter and nonlinear spacetime geometry, in a data-driven setting. For the first time in 25 years, we find evidence that the Pantheon+ catalogue already contains such a wealth of data that with further reanalysis, a genuine “paradigm shift” may soon emerge. [Abridged]
Send To > Keep unreadDelete
from
by
Robert B. Mann, Sebastian Murk, Daniel R. Terno
Fri Nov 03 2023 17:49:23 (14 hours)
# 4.
The information loss paradox is widely regarded as one of the biggest open problems in theoretical physics. Several classical and quantum features must be present to enable its formulation. First, an event horizon is needed to justify the objective status of tracing out degrees of freedom inside the black hole. Second, evaporation must be completed (or nearly completed) in finite time according to a distant observer, and thus the formation of the black hole should also occur in finite time. In spherical symmetry these requirements constrain the possible metrics strongly enough to obtain a unique black hole formation scenario and match their parameters with the semiclassical results. However, the two principal generalizations of surface gravity, the quantity that determines the Hawking temperature, do not agree with each other on the dynamical background. Neither can correspond to the emission of nearly-thermal radiation. We infer from this that the information loss problem cannot be consistently posed in its standard form.
Send To > Keep unreadDelete
from
Fri Nov 03 2023 10:20:47 (22 hours)
# 5.
Hildebrand, Tyler (2023) The Ideology of Pragmatic Humeanism. [Preprint]
Send To > Keep unreadDelete
from
by
Gabriele Gionti S.J
Tue Oct 31 2023 16:20:20 (3 days)
# 6.
A short phenomenological account of the genesis and evolution of the universe is presented with emphasis on the primordial phases as well as its physical composition, i.e. dark matter and dark energy. We discuss Einstein’s theory of General Relativity and its consequences for the birth of modern relativistic astrophysics. We introduce the Big-Bang theory of Mons. Lemaitre as well as the competing theory of the Steady State Universe of Fred Hoyle. Since Big-Bang theory appeared quite in agreement with Christian doctrine of creation, Pope Pius XII delivered a message to the pontifical Academy of Sciences in 1951 claiming a certain agreement between the creation account in the book of Genesis and the Big-Bang theory (a concordist view), a position which he did not repeat later. On the other hand, Lemaitre always kept separate the scientific and theological planes as two parallel “lines” never intersecting, i.e., as two complementary “magisteria”. Similar kind of tensions, between science and theology, emerge also today with the Hartle-Hawking solution to the Wheeler-DeWitt equation in quantum cosmology and its related speculations. To avoid some sort of confusion between theological and physics concepts, we, briefly, summarise the concept of creation in Christian theology.
Send To > Keep unreadDelete
from
by
Huw Price, Ken Wharton
Tue Oct 31 2023 16:20:19 (3 days)
# 7.
We show that Bell correlations may arise as a special sort of selection artefact, produced by ordinary control of the initial state of the experiments concerned. This accounts for nonlocality, without recourse to any direct spacelike causality or influence. The argument improves an earlier proposal in (arXiv:2101.05370v4 [quant-ph], arXiv:2212.06986 [quant-ph]) in two main respects: (i) in demonstrating its application in a real Bell experiment; and (ii) in avoiding the need for a postulate of retrocausality.
Send To > Keep unreadDelete
from
Tue Oct 31 2023 12:10:23 (3 days)
# 8.
Vassallo, Antonio and Naranjo, Pedro (2023) On the Prospects of a de Broglie-Bohm-Barbour-Bertotti Theory. [Preprint]
Send To > Keep unreadDelete
from
Tue Oct 31 2023 12:10:20 (3 days)
# 9.
Vaidman, Lev (2022) Transfer of quantum information in teleportation. [Preprint]
Send To > Keep unreadDelete
from
Mon Oct 30 2023 14:14:43 (4 days)
# 10.
Verrill, Robert (2023) The EPR-Bohm Paradox and Kent’s One-World Solution. [Preprint]
Send To > Keep unreadDelete
from
Sun Oct 29 2023 14:02:50 (5 days)
# 11.
Ovidiu Cristinel, Stoica (2023) The prince and the pauper. A quantum paradox of Hilbert-space fundamentalism. [Preprint]
Send To > Keep unreadDelete
from
Sun Oct 29 2023 14:01:57 (5 days)
# 12.
Suárez, Mauricio and Sánchez-Gómez, Pedro J. (2023) Reactivity in Chemistry: The Propensity View.
Send To > Keep unreadDelete
from
by
Raoni Arroyo, Felipe S. Abrahão
Sat Oct 28 2023 10:03:21 (6 days)
# 13.
We offer an argument against simplicity as a sole intrinsic criterion for nomic realism. The argument is based on the simplicity bubble effect. Underdetermination in quantum foundations illustrates the case.
Send To > Keep unreadDelete
from
Sat Oct 28 2023 08:02:59 (1 week)
# 14.
Franklin, Alexander (2023) Incoherent? No, Just Decoherent: How Quantum Many Worlds Emerge. [Preprint]
Send To > Keep unreadDelete
from
Sat Oct 28 2023 08:02:12 (1 week)
# 15.
Glick, David and Le Bihan, Baptiste (2023) Metaphysical Indeterminacy in Everettian Quantum Mechanics. [Preprint]
Send To > Keep unreadDelete
from
Sat Oct 28 2023 08:01:50 (1 week)
# 16.
Franklin, Alexander (2023) A Challenge for Humean Everettians. [Preprint]
