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Related papers: On the Origin of Time and the Universe

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The local Lorentz and diffeomorphism symmetries of Einstein's gravitational theory are spontaneously broken by a Higgs mechanism by invoking a phase transition in the early Universe, at a critical temperature $T_c$ below which the symmetry…

General Relativity and Quantum Cosmology · Physics 2014-11-17 J. W. Moffat

I examine two cosmological scenarios in which the thermodynamic arrow of time points in opposite directions in the asymptotic past and future. The first scenario, suggested by Aguirre and Gratton, assumes that the two asymptotic regions are…

High Energy Physics - Theory · Physics 2013-08-28 Alexander Vilenkin

Our observed Universe has a very strong arrow of time rooted in its low entropy starting point. This low entropy start can be related to various "tuning puzzles" about the early state of the Universe. Here we explore the relationship…

High Energy Physics - Theory · Physics 2022-12-28 Andreas Albrecht , Rose Baunach , Andrew Arrasmith

The thermodynamic arrow-of-time problem is thought to be resolved by the observation that our universe initially was---and still is---far from equilibrium. The psychological arrow-of-time problem is often attributed the same resolution, but…

Cosmology and Nongalactic Astrophysics · Physics 2018-12-19 Lucas Johns

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

The problem of time is a deep paradox in our physical description of the world. According to Aristotle's relational theory, time is a measure of change and does not exist on its own. In contrast, quantum mechanics, just like Newtonian…

Quantum Physics · Physics 2015-01-23 Dries Sels , Michiel Wouters

Scientists continue to wrestle with the enigma of time. Is time a dynamic or a fundamental property of spacetime? Why does it have an arrow pointing from past to future? Why are physical laws time-symmetric in a universe with broken…

General Relativity and Quantum Cosmology · Physics 2009-09-15 L. Mersini-Houghton

Our universe seems to be radiation dominated at early times, and vacuum energy dominated at late times. When we consider the maximal analytic extension of this spacetime, its symmetries and complex analytic properties suggest a picture in…

High Energy Physics - Theory · Physics 2021-09-15 Latham Boyle , Neil Turok

Theories of emergent gravity have established a deep connection between entropy and the geometry of spacetime by looking at the latter through a thermodynamic lens. In this framework, the macroscopic properties of gravity arise in a…

General Relativity and Quantum Cosmology · Physics 2025-12-01 Valeria Rossi , Sergio Luigi Cacciatori , Alessandro Pesci

We derive the arrows of time of our universe that follow from the no-boundary theory of its quantum state (NBWF) in a minisuperspace model. Arrows of time are viewed four-dimensionally as properties of the four-dimensional Lorentzian…

High Energy Physics - Theory · Physics 2013-09-04 James Hartle , Thomas Hertog

This thesis addresses two major problems in the philosophy of physics. The first is how to identify the minimal physical content of a theory; that is, what features of a theory are truly needed to make predictions, and what can be removed…

History and Philosophy of Physics · Physics 2025-09-19 Sean Gryb

Arrows of time - thermodynamical, cosmological, electromagnetic, quantum mechanical, psychological - are basic properties of Nature. For a quantum system-bath closed system the de-correlated initial conditions and no-memory (Markovian)…

Cosmology and Nongalactic Astrophysics · Physics 2017-03-22 V. G. Gurzadyan , S. Sargsyan , G. Yegorian

It is generally believed that a cosmological arrow of time must be associated with entropy production. Indeed, in his seminal work on cyclic cosmology, Tolman introduced a viscous fluid in order to make successive expansion/contraction…

General Relativity and Quantum Cosmology · Physics 2018-10-26 Varun Sahni , Yuri Shtanov , Aleksey Toporensky

Deriving an arrow of time from time-reversal symmetric microscopic dynamics is a fundamental open problem in many areas of physics, ranging from cosmology, to particle physics, to thermodynamics and statistical mechanics. Here we focus on…

Quantum Physics · Physics 2025-01-31 Thomas Guff , Chintalpati Umashankar Shastry , Andrea Rocco

All the laws of physics are time-reversible. Time arrow emerges only when ensembles of classical particles are treated probabilistically, outside of physics laws, and the entropy and the second law of thermodynamics are introduced. In…

Quantum Physics · Physics 2021-03-16 Davi Geiger , Zvi M. Kedem

One of the most difficult problems in the foundations of physics is what gives rise to the arrow of time. Since the fundamental dynamical laws of physics are (essentially) symmetric in time, the explanation for time's arrow must come from…

History and Philosophy of Physics · Physics 2021-10-26 Eddy Keming Chen

The evidence for a Big Bang origin of the Universe is truly compelling, though its cause remains a complete mystery. As the cosmic spacetime is revealed to us with ever improving detail, however, we are beginning to refine the range of its…

Cosmology and Nongalactic Astrophysics · Physics 2023-08-01 Fulvio Melia

This paper is a natural continuation of our previous paper arXiv:1011.4173 . We illustrated earlier that in classical Hamilton mechanics, for overwhelming majority of real chaotic macroscopic systems, alignment of their thermodynamic time…

General Physics · Physics 2013-07-15 Oleg Kupervasser

How does the arrow of time (dissipative, irreversible behavior) emerge from time-reversible Hamiltonian mechanics? Two ingredients are needed: the underlying system must be ergodic or phase-mixing, and our knowledge of the system must be…

Statistical Mechanics · Physics 2026-03-24 Katerina Mlada , Michal Pavelka , Vaclav Klika

Within the general formalism of quantum theory irreversibility and the arrow of time in the evolution of various physical systems are studied. Irreversible behavior often manifests itself in the guise of entropy production. This motivates…

Quantum Physics · Physics 2022-02-10 Jürg Fröhlich