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Related papers: A Note on the Cardy-Verlinde Formula

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Through the consideration of spherically symmetric gravitating systems consisting of perfect fluids with linear equation of state constrained to be in a finite volume, an account is given of the properties of entropy at conditions in which…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Alessandro Pesci

Based on the cosmic holographic conjecture of Fischler and Susskind, we point out that the average energy density of the universe is bound from above by its entropy limit. Since Friedmann's equation saturates this relation, the measured…

High Energy Physics - Theory · Physics 2007-05-23 Csaba Balazs , Istvan Szapudi

In effective field theory, the positivity bounds of higher derivative operators are derived from analyticity, causality, and unitarity. We show that the positivity bounds on some operators of the effective field theory, e.g.,…

High Energy Physics - Theory · Physics 2023-08-02 Qing-Hong Cao , Daiki Ueda

The idea that the universe has zero total energy when one includes the contribution from the gravitational field is reconsidered. A Hamiltonian is proposed as an energy for the exact equations of FRW cosmology: it is then shown that this…

Astrophysics · Physics 2009-11-07 V. Faraoni , F. I. Cooperstock

The Kerr/CFT correspondence has been recently broadened to the general extremal black holes under the assumption that the central charges from the non-gravitational fields vanish. To confirm this proposal, we derive the expression of the…

High Energy Physics - Theory · Physics 2009-06-10 Geoffrey Compère , Keiju Murata , Tatsuma Nishioka

It has been suggested heuristically by Unruh and Wald, and independently by Page, that among systems with given energy and volume, thermal radiation has the largest entropy. The suggestion leads to the corresponding universal bound on…

High Energy Physics - Theory · Physics 2008-11-26 Itzhak Fouxon

Quantities associated with Casimir forces are calculated in a model wave system of one spatial dimension with Dirichlet or Neumann boundary conditions. 1)Due to zero-point fluctuations, a partition is attracted to the walls of a box if the…

Quantum Physics · Physics 2009-11-07 Timothy H. Boyer

General relativistic entropic acceleration theory may explain the present cosmic acceleration from first principles without the need of introducing a cosmological constant. Following the covariant formulation of non-equilibrium phenomena in…

General Relativity and Quantum Cosmology · Physics 2021-10-20 Juan Garcia-Bellido , Llorenc Espinosa-Portales

We show that in the standard derivation of the holographic dark energy some conceptual issues are present. In particular, the formula used in the literature to avoid black holes is not suitable in expanding universes. A more suitable…

General Relativity and Quantum Cosmology · Physics 2013-12-11 Stefano Viaggiu

We consider the generalization of the Araki-Uhlmann formula for relative entropy to Petz-R\'enyi relative entropy. We compute this entropy for a free scalar field in the Minkowski wedge between the vacuum and a coherent state, as well as…

Mathematical Physics · Physics 2025-03-18 Markus B. Fröb , Leonardo Sangaletti

In a recent paper hep-th/0008140 by E. Verlinde, an interesting formula has been put forward, which relates the entropy of a conformal formal field in arbitrary dimensions to its total energy and Casimir energy. This formula has been shown…

High Energy Physics - Theory · Physics 2009-11-07 Rong-Gen Cai

We consider cosmological models with a scalar field with equation of state $w\ge 1$ that contract towards a big crunch singularity, as in recent cyclic and ekpyrotic scenarios. We show that chaotic mixmaster oscillations due to anisotropy…

High Energy Physics - Theory · Physics 2016-09-06 Joel K. Erickson , Daniel H. Wesley , Paul J. Steinhardt , Neil Turok

In this paper we show that the entropy of a cosmological horizon in topological Reissner-Nordstr\"om- de Sitter and Kerr-Newman-de Sitter spaces can be described by the Cardy-Verlinde formula, which is supposed to be an entropy formula of…

High Energy Physics - Theory · Physics 2007-05-23 M R Setare

An entropic-force scenario, i.e., entropic cosmology, assumes that the horizon of the universe has an entropy and a temperature. In the present study, in order to examine entropic cosmology, we derive entropic-force terms not only from the…

Cosmology and Nongalactic Astrophysics · Physics 2013-10-30 Nobuyoshi Komatsu , Shigeo Kimura

In this paper we discuss thermodynamics of apparent horizon of an $n$-dimensional Friedmann-Robertson-Walker (FRW) universe embedded in an $(n+1)$-dimensional AdS spacetime. By using the method of unified first law, we give the explicit…

High Energy Physics - Theory · Physics 2008-11-26 Rong-Gen Cai , Li-Ming Cao

We present large scale simulations for a one-dimensional chain of hard-point particles with alternating masses. We correct several claims in the recent literature based on much smaller simulations. Both for boundary conditions with two heat…

Chaotic Dynamics · Physics 2009-11-07 Peter Grassberger , Walter Nadler , Lei Yang

In the present paper we investigate thermal fluctuation corrections to the vacuum energy at zero temperature of a conformally coupled massless scalar field whose modes propagate in the Einstein universe with a spherical boundary,…

High Energy Physics - Theory · Physics 2022-11-18 Herondy F. S. Mota , Celio R. Muniz , Valdir B. Bezerra

This work considers how exponential corrections to the Bekenstein-Hawking entropy formula affect the thermodynamic behavior of the FLRW cosmological model. These corrections drastically change the form of the Friedman field equations…

High Energy Physics - Theory · Physics 2025-11-25 Rodrigo Rivadeneira-Caro , Joel F. Saavedra , Francisco Tello-Ortiz

The evolution of matter in the expanding FRW universe during the time interval between the end of inflation and the beginning of the radiation-dominated era is studied. A constraint between the global geometry and total amount of matter in…

General Relativity and Quantum Cosmology · Physics 2013-11-22 V. E. Kuzmichev , V. V. Kuzmichev

With entropic interpretation of gravity proposed by Verlinde, we obtain the Friedmann equation of the Friedmann-Robertson-Walker universe for the deformed Ho\v{r}ava-Lifshitz gravity. It is shown that, when the parameter of…

High Energy Physics - Theory · Physics 2011-09-23 Shao-Wen Wei , Yu-Xiao Liu , Yong-Qiang Wang