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Related papers: Arrow(s) of Time without a Past Hypothesis

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We address a long-standing misperception on the gravitational ``arrow of time'', a proposal by Penrose (also known as the ``Weyl-curvature hypothesis") that associates structure formation along timelike directions in which Weyl-curvature…

General Relativity and Quantum Cosmology · Physics 2025-12-03 Roberto A. Sussman , Sebastián Nájera , Fernando A. Pizaña , Juan Carlos Hidalgo

In the joint paper "Bridging the neuroscience and physics of time" Rovelli, as the physicist coauthor of neuroscientist Dean Buonomano, makes statements that rely on theoretical frameworks employed when the laws of thermodynamics and…

General Relativity and Quantum Cosmology · Physics 2022-11-28 Julian Barbour

The only widely accepted explanation for the various arrows of time that everywhere and at all epochs point in the same direction is the `past hypothesis': the Universe had a very special low-entropy initial state. We present the first…

General Relativity and Quantum Cosmology · Physics 2014-12-11 Julian Barbour , Tim Koslowski , Flavio Mercati

We advance a new viewpoint on the connection between the the thermodynamical and cosmological arrows of time, which can be traced via the properties of Cosmic Microwave Background (CMB) radiation. We show that in the…

Astrophysics · Physics 2008-11-26 A. E. Allahverdyan , V. G. Gurzadyan

Recently, a substantial amount of debate has grown up around a proposed quantum resolution to the `arrow of time dilemma' that is based on the role of classical memory records of entropy-decreasing events. In this note we show that the…

Quantum Physics · Physics 2015-05-14 David Jennings , Terry Rudolph

The arrow of time dilemma: the laws of physics are invariant for time inversion, whereas the familiar phenomena we see everyday are not (i.e. entropy increases). I show that, within a quantum mechanical framework, all phenomena which leave…

Quantum Physics · Physics 2010-04-22 Lorenzo Maccone

In this paper, we investigate an important issue addressed by several approaches to quantum cosmology, like that based on loop quantum gravity and string theory: the existence of an arrow of time driving the cosmological evolution according…

General Relativity and Quantum Cosmology · Physics 2026-03-25 Carlos Silva , Renan Aragão , Francisco A. Brito

The outcome of a single quantum experiment is unpredictable, except in a pure-state limit. The definite process that takes place in the apparatus may either be intrinsically random or be explainable from a deeper theory. While the first…

Quantum Physics · Physics 2015-06-22 Theo M. Nieuwenhuizen

Inflation allows the problem of the Arrow of time to be understood as a question about the structure of spacetime: why was the intrinsic curvature of the earliest spatial sections so much better behaved than it might have been? This is…

High Energy Physics - Theory · Physics 2008-11-26 Brett McInnes

We observe entropy decrease towards the past. Does this imply that in the past the world was in a non-generic microstate? I point out an alternative. The subsystem to which we belong interacts with the universe via a relatively small number…

History and Philosophy of Physics · Physics 2016-01-21 Carlo Rovelli

We discuss the arrow of time in terms of the increase of correlations between the system and its environment. Here we show that the existence of the arrow of time, based on deleting correlations, requires a strict absence of initial…

Quantum Physics · Physics 2016-05-04 Vlatko Vedral

What is the physical origin of the arrow of time? It is a commonly held belief in the physics community that it relates to the increase of entropy as it appears in the statistical interpretation of the second law of thermodynamics. At the…

Statistical Mechanics · Physics 2023-04-19 Andreas Henriksson

A possible mechanism of time is formulated by developing an idea of time replaced by quantum correlations, with the aid of modern quantum information theory. We invent a microscopic model, where correlations of a closed system are steadily…

Quantum Physics · Physics 2011-11-14 Akimasa Miyake

In contrast to claims by Barbour, Koslowski and Mercati, their "Janus point solution" does require a very improbable selection condition. While gravitational contraction in an expanding universe may then represent the master arrow of time,…

General Relativity and Quantum Cosmology · Physics 2016-01-13 H. Dieter Zeh

The spread of the time arrows from the environment to an observed subsystem is followed within a harmonic model. A similarity is pointed out between irreversibility and a phase with spontaneously broken symmetry. The causal structure of…

High Energy Physics - Theory · Physics 2012-06-26 Janos Polonyi

J.M.R. Parrondo at al. in arXiv:0904.1573 continue numerous efforts to unify the concepts of the arrow of time and entropy production with the concept of time invariance in physics. This is a wrong way.

General Physics · Physics 2009-07-27 V. A. Kuz'menko

Most attempts to argue for the second law of thermodynamics fail because (1) they use the unviable frequency theory of probability and (2) they do not explain why the arrow of time seen in experiments is aligned with the thermodynamic arrow…

Quantum Physics · Physics 2008-11-24 Alan Forrester

We investigate the origin of the arrow of time in quantum mechanics in the context of quantum cosmology. The ``Copenhagen'' quantum mechanics of measured subsystems incorporates a fundamental arrow of time. Extending discussions of…

General Relativity and Quantum Cosmology · Physics 2009-09-25 Murray Gell-Mann , James B. Hartle

Regardless of studies and debates over a century, the statistical origin of the second law of thermodynamics still remains illusive. One essential obstacle is the lack of a proper theoretical formalism for non-equilibrium entropy. Here I…

Statistical Mechanics · Physics 2017-10-18 Xiangjun Xing

We investigate the thermodynamic arrow of time in a time-symmetrically recollapsing universe by calculating quantum mechanically the entropy production of a massive scalar field. It is found that even though the Hamiltonian has a…

General Relativity and Quantum Cosmology · Physics 2011-04-15 Sang Pyo Kim