English
Related papers

Related papers: The Time-Asymmetry and the Entropy Gap

200 papers

Astrophysical observations provide a picture of the universe as a 4-dim homogeneous and isotropic flat space-time dominated by an unknown form of dark energy. To achieve such a cosmology one has to consider in the early universe an…

Astrophysics · Physics 2009-11-10 F. Canfora , A. Troisi

If we look from a quantum perspective, the most natural way in which the universe can be created is in entangled pairs whose time flow is oppositely related. This suggests the idea of the creation of a universe-antiuniverse pair. Assuming…

General Relativity and Quantum Cosmology · Physics 2025-09-29 Naman Kumar

We estimate the entropy associated to a background of squeezed cosmic gravitons, and we argue that the process of cosmological pair production from the vacuum may explain the large amount of entropy of our present universe.

General Relativity and Quantum Cosmology · Physics 2009-10-22 M. Gasperini , M. Giovannini

Physics takes for granted that interacting physical systems with no common history are independent, before their interaction. This principle is time-asymmetric, for no such restriction applies to systems with no common future, after an…

Quantum Physics · Physics 2007-05-23 Huw Price

Quantum physics, despite its observables being intrinsically of a probabilistic nature, does not have a quantum entropy assigned to them. We propose a quantum entropy that quantify the randomness of a pure quantum state via a conjugate pair…

Quantum Physics · Physics 2022-10-05 Davi Geiger , Zvi M. Kedem

Deutsch and Aguirre have recently shown that the solutions of certain dynamical systems typically contain a point of minimum size that they identify as an entropy minimum and from which the size and entropy increase to infinity in both…

General Relativity and Quantum Cosmology · Physics 2021-08-24 Julian Barbour

The energy densities of matter and the vacuum are currently observed to be of the same order of magnitude: $(\Omega_{m 0} \approx 0.3) \sim (\Omega_{\Lambda 0} \approx 0.7)$. The cosmological window of time during which this occurs is…

Astrophysics · Physics 2009-11-13 Charles H. Lineweaver , Chas A. Egan

We address how to construct an infinitely cyclic universe model. A major consideration is to make the entropy cyclic which requires the entropy to be reset to zero in each cycle expansion to turnaround, to contraction, to bounce, etc. Here…

General Relativity and Quantum Cosmology · Physics 2015-08-06 Paul Howard Frampton

We consider an evolution of anisotropic cosmological model on the example of the Bianchi type I homogeneous universe. It is filled by the mixture of matter and dark energy with an arbitrary barotropic equation of state (EoS). The general…

General Relativity and Quantum Cosmology · Physics 2023-06-14 S L Parnovsky

Topological defects are common in many everyday systems. In general, they appear if a symmetry is broken at a rapid phase transition. In this article, I explain why it is believed that they should have also been formed in the early universe…

Astrophysics · Physics 2007-05-23 A. Rajantie

Old and new puzzles of cosmology are reexamined from the point of view of quantum theory of the universe developed here. It is shown that in proposed approach the difficulties of the standard cosmology do not arise. The theory predicts the…

Astrophysics · Physics 2011-09-13 V. E. Kuzmichev , V. V. Kuzmichev

Standard calculations suggest that the entropy of our universe is dominated by black holes, whose entropy is of order their area in Planck units, although they comprise only a tiny fraction of its total energy. Statistical entropy is the…

High Energy Physics - Theory · Physics 2009-09-17 Paul Frampton , Stephen D. H. Hsu , Thomas W. Kephart , David Reeb

In a recent model Choudhury proposed that a collapsing matter generates an adiabatic pressure which can be used to explain the acceleration of the physical universe under certain approximation. In this work we superimpose the core pressure…

General Relativity and Quantum Cosmology · Physics 2008-05-26 A. M. Haruar Rashid , A. L. Choudhury

The relative entropy of two n-party quantum states is an important quantity exhibiting, for example, the extent to which the two states are different. The relative entropy of the states formed by reducing two n-party to a smaller number $m$…

Quantum Physics · Physics 2017-08-02 Ben Ibinson , Noah Linden , Andreas Winter

A scenario of an emergent universe is constructed in the background of an inhomogeneous space-time model which is asymptotically (at spatial infinity) FRW space-time. The cosmic substratum consists of non-interacting two components, namely…

General Relativity and Quantum Cosmology · Physics 2016-01-18 Subhra Bhattacharya , S. Chakraborty

We argue that (1) our perception of time through change and (2) the gap between reality and our observation of it are at the heart of both quantum mechanics and the dynamical mechanism of physical systems. We suggest that the origin of…

General Physics · Physics 2014-07-15 Michael York

When $t\to \infty $ any wave packet in the liouvillian representation of the density matrices, becomes a Hardy class function from below. This fact, in the global frame of Reichenbach diagram, is used to explain the observed global time…

Mathematical Physics · Physics 2015-06-26 Mario A. Castagnino , Jorge Gueron , Adolfo Ordoniez

Cosmic acceleration is explained quantitatively, purely in general relativity, as an apparent effect due to quasilocal gravitational energy differences that arise in the decoupling of bound systems from the global expansion of the universe.…

General Relativity and Quantum Cosmology · Physics 2008-11-26 David L. Wiltshire

The cosmological constant $\Lambda$ used to be a freedom in Einstein's theory of general relativity, where one had a proclivity to set it to zero purely for convenience. The signs of $\Lambda$ or $\Lambda$ being zero would describe…

General Relativity and Quantum Cosmology · Physics 2017-08-22 Vee-Liem Saw

In classical Hamiltonian theories, entropy may be understood either as a statistical property of canonical systems, or as a mechanical property, that is, as a monotonic function of the phase space along trajectories. In classical mechanics,…

General Relativity and Quantum Cosmology · Physics 2016-10-14 Marius Oltean , Luca Bonetti , Alessandro D. A. M. Spallicci , Carlos F. Sopuerta
‹ Prev 1 4 5 6 7 8 10 Next ›