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Related papers: Thermodynamics of the FLRW apparent horizon in Ein…

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To investigate the relationship between gravity and thermodynamics in the case of dynamic systems, we interpret the apparent horizon of the Friedmann-Lema\^itre-Robertson-Walker (FLRW) spacetime as a thermodynamic system. We derive the…

General Relativity and Quantum Cosmology · Physics 2023-03-22 Luis M. Sanchez , Hernando Quevedo

It is shown that the differential form of Friedmann equation of a FRW universe can be rewritten as a universal form $dE = TdS + WdV$ at apparent horizon, where $E$ and $V$ are the matter energy and volume inside the apparent horizon (the…

High Energy Physics - Theory · Physics 2008-11-26 M. Akbar , Rong-Gen Cai

In this paper we study the recently proposed $f(R,\mathcal{L})$ theories from a thermodynamic point of view. The uniqueness of these theories lies in the fact that the space-time curvature is coupled to the baryonic matter instead of exotic…

General Physics · Physics 2020-05-06 Behnam Pourhassan , Prabir Rudra

In this paper, we investigate the thermodynamic aspects of quadratic gravity in a $D$-dimensional Friedmann-Lemaitre-Robertson-Walker (FLRW) universe. First, we derive the field equations and the effective energy-momentum tensor for…

General Relativity and Quantum Cosmology · Physics 2025-07-17 Navid Safarzadeh Ilkhchi , Amin Rezaei Akbarieh , Yaghoub Heydarzade

Starting from the first law of thermodynamics, $dE=T_hdS_h+WdV$, at apparent horizon of a FRW universe, and assuming that the associated entropy with apparent horizon has a quantum corrected relation, $S=\frac{A}{4G}-\alpha \ln…

High Energy Physics - Theory · Physics 2011-02-09 Ahmad Sheykhi

In the context of the teleparallel equivalent of general relativity the concept of gravitational pressure and gravitational energy-momentum arisen in a natural way. In the case of a Friedmann-Lemaitre-Robertson-Walker space FLRW we obtain…

General Relativity and Quantum Cosmology · Physics 2018-02-19 J. F. da Rocha-Neto , B. R. Morais

Thermodynamics on the cosmological apparent horizon of a flat Friedmann-Lemaitre-Robertson-Walker metric has been investigated with Bekenstein entropy and Hawking temperature on the horizon, and Unruh temperature for the fluid inside the…

General Relativity and Quantum Cosmology · Physics 2016-07-15 Subhajit Saha

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 propose a modified gravity theory by extending the Einstein-Hilbert action with an arbitrary function of the Ricci scalar and the Kretschmann scalar invariants. The resulting modified Friedmann equations for a spatially flat FRW universe…

General Relativity and Quantum Cosmology · Physics 2026-05-29 A. Dehyadegari , A. Sheykhi

Recently, we have generalized the Bekenstein-Hawking entropy formula for black holes embedded in expanding Friedmann universes. In this letter, we begin the study of this new formula to obtain the first law of thermodynamics for dynamical…

High Energy Physics - Theory · Physics 2015-08-11 Stefano Viaggiu

With the usual definitions for the entropy and the temperature associated with the apparent horizon, we discuss the first law of the thermodynamics on the apparent in the general scalar-tensor theory of gravity with the kinetic term of the…

General Relativity and Quantum Cosmology · Physics 2016-03-04 Yumei Huang , Yungui Gong

We assume the non-flat Friedmann-Robertson-Walker (FRW) Universe as a thermodynamical system. We assume the cosmological horizon as a inner trapping horizon which is treated as dynamical apparent horizon of FRW Universe. We write the…

General Relativity and Quantum Cosmology · Physics 2020-10-06 Ujjal Debnath

We investigate the validity of generalized second law of thermodynamics of a physical system comprising of newly proposed dark energy model called Ricci Gauss-Bonnet and cold dark matter enveloped by apparent horizon and event horizon in…

General Relativity and Quantum Cosmology · Physics 2018-03-12 Ayesha Iqbal , Abdul Jawad

With the usual definitions for the entropy and the temperature associated with the apparent horizon, we show that the unified first law on the apparent horizon is equivalent to the Friedmann equation for the scalar--tensor theory with…

General Relativity and Quantum Cosmology · Physics 2015-07-31 Yumei Huang , Yungui Gong , Dicong Liang , Zhu Yi

We consider a spatially flat Friedmann-Lemaitre-Robertson-Walker space time and investigate the second law and the generalized second law of thermodynamics for apparent horizon in generalized modified Gauss Bonnet theory of gravity (whose…

General Relativity and Quantum Cosmology · Physics 2011-01-17 H. Mohseni Sadjadi

We derive the modified Friedmann equation corresponding to the power-law corrected entropy-area relation $S_{\rm A}=\frac{A}{4}[1-K_{\alpha} A^{1-\frac{\alpha}{2}}]$ which is motivated by the entanglement of quantum fields in and out of the…

General Physics · Physics 2011-09-07 K. Karami , A. Abdolmaleki , N. Sahraei , S. Ghaffari

By applying the unified first law of thermodynamics on the apparent horizon of FRW universe, we get the entropy relation for the apparent horizon in quasi-topological gravity theory. Throughout the paper, the results of considering the…

General Relativity and Quantum Cosmology · Physics 2016-05-17 H. Moradpour , R. Dehghani

Thermodynamic interpretations of gravity often arise from applying the Clausius relation to spacetime horizons. In modified gravity theories with higher-order equations of motion, such as f(R) and scalar-tensor gravity, this relation…

General Relativity and Quantum Cosmology · Physics 2026-04-07 Vishnu A Pai , Vishnu S Namboothiri , Titus K Mathew

We have investigated the thermodynamical properties of the Universe with dark energy. Adopting the usual assumption in deriving the constant co-moving entropy density that the physical volume and the temperature are independent, we observed…

General Relativity and Quantum Cosmology · Physics 2010-10-27 Yungui Gong , Bin Wang , Anzhong Wang

The question that continues to hinge the interrelation between cosmology and thermodynamics is broadly described as -- what is the form of horizon entropy that links the Friedmann equations for a "$general$" gravity theory with the…

General Relativity and Quantum Cosmology · Physics 2024-01-30 Shin'ichi Nojiri , Sergei D. Odintsov , Tanmoy Paul , Soumitra SenGupta
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