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Related papers: A covariant entropy bound conjecture on the dynami…

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Recently a covariant entropy conjecture has been proposed for dynamical horizons. We apply this conjecture to concordance cosmological models, namely, those cosmological models filled with perfect fluids, in the presence of a positive…

High Energy Physics - Theory · Physics 2008-11-26 Song He , Hongbao Zhang

We here propose a covariant entropy conjecture on cosmological dynamical horizon. After the formulation of our conjecture, we test its validity in adiabatically expanding universes with open, flat and closed spatial geometry, where our…

High Energy Physics - Theory · Physics 2008-11-26 Song He , Hongbao Zhang

The covariant entropy bound conjecture is an important hint for the quantum gravity, with several versions available in the literature. For cosmology, Ashtekar and Wilson-Ewing ever show the consistence between the loop gravity theory and…

General Relativity and Quantum Cosmology · Physics 2015-05-14 Li-Fang Li , Jian-Yang Zhu

In this letter, we propose a new generalized mass-to-horizon relation to be used in the context of entropic cosmologies and holographic principle scenarios. We show that a general scaling of the mass with the Universe horizon as $M=\gamma…

General Relativity and Quantum Cosmology · Physics 2024-05-02 Hussain Gohar , Vincenzo Salzano

Based on an analysis of the entropy associated to the vacuum quantum fluctuations, we show that the holographic principle, applied to the cosmic scale, constitutes a possible explanation for the observed value of the cosmological constant,…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Saulo Carneiro

This article is dedicated to establishing a novel approach to the cosmological constant, in which it is treated as an eigenvalue of a certain Sturm--Liouville problem. The key to this approach lies in the proper formulation of physically…

High Energy Physics - Theory · Physics 2023-01-02 Artyom Yurov , Valerian Yurov

We analyze the validity of the generalized covariant entropy bound near the apparent horizon of isotropic expanding cosmological models. We encounter violations of the bound for cosmic times smaller than a threshold. By introducing an…

High Energy Physics - Theory · Physics 2007-05-23 M. A. Per , A. Segui

The author proposed in his previous papers in 2001 that the problem of the cosmological constant could be resolved and its calculated value agrees excellently with the observations by assuming that the space-time itself, as the phase of…

General Physics · Physics 2007-05-23 H. M. Mok

A simple derivation of the bound on entropy is given and the holographic principle is discussed. We estimate the number of quantum states inside space region on the base of uncertainty relation. The result is compared with the Bekenstein…

General Relativity and Quantum Cosmology · Physics 2015-06-25 M. G. Ivanov , I. V. Volovich

According to the holographic principle, the maximum amount of information stored in a region of space scales as the area of its two-dimensional surface, like a hologram. We show that the holographic principle can be understood heuristically…

General Relativity and Quantum Cosmology · Physics 2016-10-21 Y. Jack Ng

We propose an infrared cut-off for the holographic density which incorporates among others a constant term, that produces the effect of the cosmological constant, improving the results of previously considered holographic models based on…

High Energy Physics - Theory · Physics 2011-01-26 L. N. Granda

In this paper we consider the implications of a cosmological constant for the evolution of the universe, under a set of assumptions motivated by the holographic and horizon complementarity principles. We discuss the ``causal patch"…

High Energy Physics - Theory · Physics 2009-11-07 Lisa Dyson , Matthew Kleban , Leonard Susskind

In this letter we explore the foundations of entropic cosmology and highlight some important flaws which have emerged and adopted in the recent literature. We argue that, when applying entropy and temperature on the cosmological horizon by…

General Relativity and Quantum Cosmology · Physics 2024-03-25 Hussain Gohar , Vincenzo Salzano

Next year we will celebrate 100 years of the cosmological term, $\Lambda$, in Einstein's gravitational field equations, also 50 years since the cosmological constant problem was first formulated by Zeldovich, and almost about two decades of…

Cosmology and Nongalactic Astrophysics · Physics 2016-12-14 Joan Sola

The causal entropic principle aims to predict the unexpectedly small value of the cosmological constant Lambda using a weighting by entropy increase on causal diamonds. The original work assumed a purely isotropic and homogeneous cosmology.…

General Relativity and Quantum Cosmology · Physics 2012-01-20 Daniel Phillips , Andreas Albrecht

Standard cosmology has long been plagued by a number of persistent problems. The origin of the apparent acceleration of the cosmic expansion remains enigmatic. The cosmological constant has been reintroduced as a free parameter with a value…

General Physics · Physics 2023-02-28 Jan O. Stenflo

The influence of recent detections of a finite vacuum energy ("cosmological constant") on our formulation of anthropic conjectures, particularly the so-called Final Anthropic Principle is investigated. It is shown that non-zero vacuum…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Milan M. Cirkovic , Nick Bostrom

The (re)introduction of $\Lambda$ into cosmology has spurred debates that touch on central questions in philosophy of science, as well as the foundations of general relativity and particle physics. We provide a systematic assessment of the…

History and Philosophy of Physics · Physics 2023-03-06 Adam Koberinski , Bridget Falck , Chris Smeenk

The cosmological constant problem is explained by a theory based on the discrete space-time hypothesis. The calculated cosmological constant value is of the order of 10^-52[m]^-2 or equivalent to about 0.7 of the critical mass density. It…

Astrophysics · Physics 2007-05-23 H. M. Mok

The holographic bound in Brans-Dicke $k=1$ matter dominated Cosmology is discussed. In this talk, both the apparent horizon and the particle horizon are taken for the holographic bound. The covariant entropy conjecture proposed by Bousso is…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Yungui Gong
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