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Related papers: Multidimensional arrow of time

200 papers

We investigate the arrow of time problem in the context of gravitational collapse of radiating stars in higher dimensions for both neutral and charged matter. The interior spacetime is described by a shear-free spherically symmetric metric…

General Relativity and Quantum Cosmology · Physics 2026-01-29 Samarjit Chakraborty , Sunil D. Maharaj , Rituparno Goswami , Sarbari Guha

We discuss how the classical notions of time and causal structure may emerge together with quantum-mechanical probabilities from a universal quantum state. For this, the process of decoherence between semiclassical branches is important.…

General Relativity and Quantum Cosmology · Physics 2025-06-24 Leonardo Chataignier , Claus Kiefer , Mritunjay Tyagi

The physical origin of spacetime discreteness remains a central open problem in quantum gravity, with most existing approaches relying on specific microscopic structures or model-dependent assumptions. In this letter, spacetime discreteness…

General Relativity and Quantum Cosmology · Physics 2026-05-26 Weihu Ma , Yu-Gang Ma

We introduce a flow in the space of constant width bodies in three-dimensional Euclidean space that simultaneously increases the volume and decreases the circumradius of the shape as time increases. Starting from any initial constant width…

Functional Analysis · Mathematics 2021-09-16 Ryan Hynd

Microphysical laws are time reversible, but macrophysics, chemistry and biology are not. This chapter explores how this asymmetry (a classic example of a broken symmetry) arises due to the cosmological context, where a non-local Direction…

General Relativity and Quantum Cosmology · Physics 2020-03-18 George F R Ellis , Barbara Drossel

Recently it has been proposed that the Bekenstein-Hawking formula for the entropy of spacetime horizons has a larger significance as the leading contribution to the entanglement entropy of general spacetime regions, in the underlying…

High Energy Physics - Theory · Physics 2014-08-27 Jason Wien

The purpose of this paper is to explain a certain dichotomy between the information that the past and future values of a multivariate stochastic process carry about the present. More specifically, vector-valued, second-order stochastic…

Optimization and Control · Mathematics 2015-07-31 Yongxin Chen , Johan Karlsson , Tryphon T. Georgiou

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

This paper is devoted to discussing the topological structure of the arrow of time. In the literature, it is often accepted that its algebraic and topological structures are that of a one-dimensional Euclidean space $\mathbb{E}^1$, although…

General Relativity and Quantum Cosmology · Physics 2022-09-23 B. F. Rizzuti , L. M. Gaio , Lucas T. Cardoso

Motivated by the mounting evidence for dark energy, here we explore the consequences of a fundamental cosmological constant $\Lambda$ for our universe. We show that when the gravitational entropy of a pure DeSitter state ultimately wins…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Laura Mersini-Houghton

We relate physical time with the topology of magnetic field vortices. We base ourselves on a formulation of unimodular gravity where the cosmological constant $\Lambda$ appears as the canonical dual to a variable which on-shell becomes…

High Energy Physics - Theory · Physics 2024-06-24 Altay Etkin , João Magueijo , Farbod-Sayyed Rassouli

The paper discusses recent proposals by Carroll and Chen, as well as Barbour, Koslowski, and Mercati to explain the (thermodynamic) arrow of time without a Past Hypothesis, i.e., the assumption of a special (low-entropy) initial state of…

History and Philosophy of Physics · Physics 2020-07-14 Dustin Lazarovici , Paula Reichert

The possibility of physics in multiple time dimensions is investigated. Drawing on recent work by Walter Craig and myself, I show that, contrary to conventional wisdom, there is a well-posed initial value problem--deterministic, stable…

General Physics · Physics 2008-12-22 Steven Weinstein

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…

High Energy Physics - Theory · Physics 2022-02-08 Jordan Cotler , Andrew Strominger

We assume that the universe consists of clusters which in turns have sub-clusters and the sub-clusters have sub-subclusters and so on. Confining to three-dimensional space, it is shown that the universe is expanding if entropy of the…

General Physics · Physics 2007-05-23 Shahid N. Afridi , M. Khalid Khan

A generalized framework is developed which uses a set description instead of wavefunction to emphasize the role of the observer. Such a framework is found to be very effective in the study of the measurement problem and time's arrow.…

Quantum Physics · Physics 2007-05-23 Zhen Wang

We study the implications of time-varying wave mechanics, and show how the standard wave equation is modified if the speed of a wave is not constant in time. In particular, waves which experience longitudinal acceleration are shown to have…

Optics · Physics 2023-04-18 Matias Koivurova , Charles W. Robson , Marco Ornigotti

Motivated by the search for a Hamiltonian formulation of Einstein equations of gravity which depends in a minimal way on choices of coordinates, nor on a choice of gauge, we develop a multisymplectic formulation on the total space of the…

Mathematical Physics · Physics 2017-01-30 Frédéric Hélein , Dimitri Vey

Various diagnostics of the emergence of an arrow of time in the bulk description of a holographic theory have been proposed, including the decay of some real time correlation functions and the appearance of type III$_1$ von Neumann algebras…

High Energy Physics - Theory · Physics 2023-10-24 Elliott Gesteau

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