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Related papers: On the Origin of Time and the Universe

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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

In several previous papers we have argued for a global and non-entropic approach to the problem of the arrow of time, according to which the ''arrow'' is only a metaphorical way of expressing the geometrical time-asymmetry of the universe.…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Matias Aiello , Mario Castagnino , Olimpia Lombardi

All differences between the role of space and time in nature are explained by proposing the principles in which none of the spacetime coordinates has an {\it a priori} special role. Spacetime is treated as a non-dynamical manifold, with a…

General Relativity and Quantum Cosmology · Physics 2023-04-25 Hrvoje Nikolic

The second law of thermodynamics is asymmetric with respect to time as it says that the entropy of the universe must have been lower in the past and will be higher in the future. How this time-asymmetric law arises from the time-symmetric…

Statistical Mechanics · Physics 2021-06-07 Sivapalan Chelvaniththilan

We present a method, which we shall call the probabilistic evolutionary process, based on the probabilistic nature of quantum theory to offer a possible solution to the problem of time in quantum cosmology. It offers an alternative for…

General Relativity and Quantum Cosmology · Physics 2009-05-06 N. Khosravi , H. R. Sepangi

Existing accounts of the cosmological arrow of time face a dilemma: generalist approaches that posit time-asymmetric laws lack independent motivation, while particularist approaches that invoke a Past Hypothesis face serious conceptual and…

History and Philosophy of Physics · Physics 2025-10-06 Sean Gryb , Simon Friederich

This paper continues the building of the cosmological theory that was introduced in two earlier papers under the title A Dust Universe Solution to the Dark Energy Problem. The model introduced in this theory has existence before time zero…

General Physics · Physics 2010-02-21 James G. Gilson

Within the framework of flux compactifications, we construct an instanton describing the quantum creation of an open universe from nothing. The solution has many features in common with the smooth 6d bubble of nothing solutions discussed…

General Relativity and Quantum Cosmology · Physics 2015-05-28 Jose J. Blanco-Pillado , Handhika S. Ramadhan , Benjamin Shlaer

The relation between the thermodynamical and cosmological arrows of time is usually viewed in the context of the initial conditions of the Universe. It is a necessary but not sufficient condition for ensuring the thermodynamical arrow. We…

Astrophysics · Physics 2018-03-28 A. E. Allahverdyan , V. G. Gurzadyan

Inspired by the entropy-area relation of black hole thermodynamics, we study the thermodynamics of cosmological apparent horizon in a spatially flat Friedmann-Robertson-Walker (FRW) universe in the framework of an Extended Uncertainty…

General Relativity and Quantum Cosmology · Physics 2024-08-29 Maryam Roushan , Narges Rashidi , Kourosh Nozari

Our conventional understanding of space-time, as well as our notion of geometry, break down once we attempt to describe the very early stages of the evolution of our universe. The extreme physical conditions near the Big Bang necessitate an…

General Relativity and Quantum Cosmology · Physics 2014-07-16 Mairi Sakellariadou

Time is absolute in standard quantum theory and dynamical in general relativity. The combination of both theories into a theory of quantum gravity leads therefore to a "problem of time". In my essay I shall investigate those consequences…

General Relativity and Quantum Cosmology · Physics 2009-09-22 Claus Kiefer

A cosmological model is proposed which uses a causality argument to solve the homogeneity and entropy problems of cosmology. In this model a chronology violating region of spacetime causally precedes the remainder of the Universe, and a…

General Physics · Physics 2014-03-31 E. Minguzzi

We discuss cosmological models for an eternal universe. Physical observables show no singularity from the infinite past to the infinite future. While the universe is evolving, there is no beginning and no end - the universe exists forever.…

General Relativity and Quantum Cosmology · Physics 2014-08-27 C. Wetterich

Physical laws for elementary particles can be described by the quantum dynamics equation given a Hamiltonian. The solution are probability amplitudes in Hilbert space that evolve over time. A probability density function over position and…

Quantum Physics · Physics 2019-12-02 Davi Geiger , Zvi M. Kedem

It is argued that the observed Thermodynamic Arrow of Time must arise from the boundary conditions of the universe. We analyse the consequences of the no boundary proposal, the only reasonably complete set of boundary conditions that has…

General Relativity and Quantum Cosmology · Physics 2009-10-22 S. W. Hawking , R. Laflamme , G. W. Lyons

In this paper we discuss the traditional approaches to the problem of the arrow of time. On the basis of this discussion we adopt a global and non-entropic approach, according to which the arrow of time has a global origin and is an…

Quantum Physics · Physics 2014-11-18 Mario Castagnino , Luis Lara , Olimpia Lombardi

We suggest that spontaneous eternal inflation can provide a natural explanation for the thermodynamic arrow of time, and discuss the underlying assumptions and consequences of this view. In the absence of inflation, we argue that systems…

High Energy Physics - Theory · Physics 2007-05-23 Sean M. Carroll , Jennifer Chen

Fisher's arrow of `time' in a cosmological phase space defined as in quantum optics (i.e., whose points are coherent states) is introduced as follows. Assuming that the phase space evolution of the universe starts from an initial squeezed…

General Relativity and Quantum Cosmology · Physics 2009-10-30 B. Roy Frieden , H. C. Rosu

Different approaches to quantum gravity, such as loop quantum cosmology and group field theory, predict the resolution of the initial cosmological singularity via a bounce: a regular spacetime region that connects the expanding branch of…

General Relativity and Quantum Cosmology · Physics 2024-11-01 Marco de Cesare