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Related papers: On the Origin of Time and the Universe

200 papers

The recent surge of interest in the origin of the temporal asymmetry of thermodynamical systems (including the accessible part of the universe itself) put forward two possible explanatory approaches to this age-old problem. Hereby we show…

Astrophysics · Physics 2007-05-23 Milan M. Cirkovic

In a unified picture both inflation and present dynamical dark energy arise from the same scalar field. The history of the Universe describes a crossover from a scale invariant "past fixed point" where all particles are massless, to a…

High Energy Physics - Theory · Physics 2015-12-09 C. Wetterich

Using a novel, string theory-inspired formalism based on a Hamiltonian constraint, we obtain a conformal mechanical system for the spatially flat four-dimensional Robertson-Walker Universe. Depending on parameter choices, this system…

High Energy Physics - Theory · Physics 2008-11-26 Johanna Erdmenger , Rene Meyer , Jeong-Hyuck Park

Starting from the classic Friedmann-Robertson-Walker theory with big bang it is shown that the solutions of the field equations can be extended to negative times. Choosing a new cosmic time scale instead of proper time one achieves complete…

General Relativity and Quantum Cosmology · Physics 2009-07-03 Joachim Schroeter

At the mesoscopic scales --- which interpolate between the macroscopic, classical, geometry and the microscopic, quantum, structure of spacetime --- one can identify the density of states of the geometry which arises from the existence of a…

General Relativity and Quantum Cosmology · Physics 2018-12-19 T. Padmanabhan

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

This paper presents a unified formulation of the origin of the arrow of time in classical and quantum mechanics. We begin with a mechanical analysis of a one-dimensional three-particle system, which provides a concrete example in which…

Statistical Mechanics · Physics 2025-12-19 Shuhei Kobayashi

Entropy and the second law of thermodynamcs were discovered through study of the behaviour of gases in confined spaces. The related techniques developed in the kinetic theory of gases have failed to resolve the apparent conflict between the…

General Relativity and Quantum Cosmology · Physics 2016-02-26 Julian Barbour

A simple and surprisingly realistic model of the origin of the universe can be developed using the Friedmann equation from general relativity, elementary quantum mechanics, and the experimental values of h, c, G and the proton mass. The…

General Relativity and Quantum Cosmology · Physics 2015-06-25 T. R. Mongan

The great emptiness is a possible beginning of the Universe in the infinite past of physical time. For the epoch of great emptiness particles are extremely rare and effectively massless. Only expectation values of fields and average…

General Relativity and Quantum Cosmology · Physics 2021-05-12 C. Wetterich

We present a cosmological model arising from a gravitational theory with an infinite tower of higher-order curvature invariants that can reproduce the entire evolution of the Universe: from inflation to late-time acceleration, without…

General Relativity and Quantum Cosmology · Physics 2022-02-10 Luisa G. Jaime , Gustavo Arciniega

Cosmic inflation claims to make the initial conditions of the standard big bang "generic". But Boltzmann taught us that the thermodynamic arrow of time arises from very non-generic ("low entropy") initial conditions. I discuss how to…

Astrophysics · Physics 2007-05-23 Andreas Albrecht

It is brought forward that viable theories of the physical world that have no variable at all that can play the role of time, do not exist; some notion of time is one of the very first ingredients a candidate theory should possess. Almost…

Quantum Physics · Physics 2018-04-05 Gerard t Hooft

The AdS/CFT correspondence, or more generally the gauge/gravity duality, is a remarkable conjecture obtained from superstring theory with various D-brane backgrounds. According to this conjecture, a higher-dimensional curved space-time…

High Energy Physics - Lattice · Physics 2012-06-01 Jun Nishimura

In light of G\"{o}del's undecidability results (incomplete theorems) for math, quantum indeterminism indicates that physics and the Universe may be indeterministic, incomplete, and open in nature, and therefore demand no single unification…

General Physics · Physics 2020-03-11 Wanpeng Tan

The BFSS matrix model is a suggested non-perturbative definition of string theory. Starting from a thermal state of this matrix model, we show how space and time can emerge dynamically. Results from the IKKT matrix model indicate that the…

High Energy Physics - Theory · Physics 2022-12-07 Suddhasattwa Brahma , Robert Brandenberger , Samuel Laliberte

This talk is about solving cosmological equations analytically without approximations, and discovering new phenomena that could not be noticed with approximate solutions. We found all the solutions of the Friedmann equations for a specific…

General Relativity and Quantum Cosmology · Physics 2011-09-30 Itzhak Bars

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

Curiously, our Universe was born in a low entropy state, with abundant free energy to power stars and life. The form that this free energy takes is usually thought to be gravitational: the Universe is almost perfectly smooth, and so can…

Cosmology and Nongalactic Astrophysics · Physics 2023-06-22 Luke A. Barnes , Geraint F. Lewis

Quantum cosmology offers a unique stage to address questions of time related to its underlying (and perhaps truly quantum dynamical) meaning as well as its origin. Some of these issues can be analyzed with a general scheme of quantum…

General Relativity and Quantum Cosmology · Physics 2012-07-25 Martin Bojowald