English
Related papers

Related papers: General Modified Friedmann Equations in Rainbow Fl…

200 papers

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

The Gravity from Entropy (GfE) action posits that gravity that is fundamentally given by the information encoded in the interplay between matter and geometry. The GfE Lagrangian is given by the Geometric Quantum Relative Entropy (GQRE)…

General Relativity and Quantum Cosmology · Physics 2026-05-12 Ginestra Bianconi

In this work, we have considered the Vaidya spacetime in null radiating fluid with perfect fluid in higher dimension and have found the solution for barotropic fluid. We have shown that the Einstein's field equations can be obtained from…

General Relativity and Quantum Cosmology · Physics 2012-10-04 Ujjal Debnath

The equations of motion describing all physical systems, except gravity, remain invariant if a constant is added to the Lagrangian. In the conventional approach, gravitational theories break this symmetry exhibited by all other physical…

General Relativity and Quantum Cosmology · Physics 2015-12-22 T. Padmanabhan

Recently, it was argued (Eur. Phys. J. C {\bf73}, 2487 (2013)) that the total entropy of a gravitational system should be related to the volume of system instead of the system surface. Here, we show that this new proposal cannot satisfy the…

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

The consequence of energy conservation in the flat Friedmannn-Robertson-Walker (FRW) cosmology is a strictly positive accelerating expansion. A mechanism is proposed for this expansion due to the effect of the attractive (negative)…

General Relativity and Quantum Cosmology · Physics 2009-01-09 Steven Maxson

We employ linearized quantum gravity to study gravitational redshift of photons in the context of relativistic and quantum physics, where photons interact in flat spacetime with a classical massive body via graviton exchange. We find that…

General Relativity and Quantum Cosmology · Physics 2026-02-05 Alessio Lapponi , Alessandro Ferreri , David Edward Bruschi

Three decades ago, Ted Jacobson surprised us with a very appealing approach to classical gravity. According to him, the gravitational field equations are the consequence of the first law of thermodynamics applied to a Rindler observer.…

General Relativity and Quantum Cosmology · Physics 2026-05-28 Jhan N. Martinez , Jose F. Rodriguez-Ruiz , Yeinzon Rodriguez

In this paper, we investigate a spinning black ring and a charged black ring in the context of gravity's rainbow. By incorporating rainbow functions proposed by Amelino-Camelia, et al. in [arXiv:hep-th/9605211, arXiv:0806.0339v2] in the…

High Energy Physics - Theory · Physics 2015-01-05 Ahmed Farag Ali , Mir Faizal , Mohammed M. Khalil

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

According to Verlinde's recent proposal, the gravity is originally an entropic force. In this work, we obtain the corrections to the entropy-area law of black holes within rainbow gravity. The corrected entropy-area law leads to the…

General Relativity and Quantum Cosmology · Physics 2017-01-25 A. S. Sefiedgar

Recently, Verlinde proposed that gravity is an emergent phenomenon which originates from an entropic force. In this work, we extend Verlinde's proposal to accommodate generalized uncertainty principles (GUP), which are suggested by some…

General Relativity and Quantum Cosmology · Physics 2024-09-20 Adel Awad , Ahmed Farag Ali

We present an alternative derivation of the gravitational field equations for Lovelock gravity starting from the Newton's law, which is closer in spirit to the thermodynamic description of gravity. As a warm up exercise, we have explicitly…

General Relativity and Quantum Cosmology · Physics 2018-04-23 Sumanta Chakraborty

We examine the consistency of the thermodynamics of the most general class of conformally flat solution with an irrotational perfect fluid source (the Stephani Universes). For the case when the isometry group has dimension $r\ge2$, the…

General Relativity and Quantum Cosmology · Physics 2015-06-25 Hernando Quevedo , Roberto Sussman

We consider universes that are close to Friedmann-Robertson-Walker in the sense that metric perturbations, their time derivatives and first spatial derivatives are small, but second spatial derivatives are not constrained. We show that if…

Cosmology and Nongalactic Astrophysics · Physics 2012-05-03 Syksy Rasanen

Rainbow gravity modifies general relativity by introducing an energy dependent metric, which is expected to have a role in the quantum theory of black holes and in quantum gravity at Planck energy scale. We show that rainbow gravity can be…

General Relativity and Quantum Cosmology · Physics 2018-06-07 Maria Chiara Braidotti , Claudio Conti

We investigate the unified first law and the generalized second law in a modified holographic dark energy model. The thermodynamical analysis on the apparent horizon can work and the corresponding entropy formula is extracted from the…

General Relativity and Quantum Cosmology · Physics 2015-06-19 Hui Li , Yi Zhang

The existence of a minimum time uncertainty is usually argued to be a consequence of the combination of quantum mechanics and general relativity. Most of the studies that point to this result are nonetheless based on perturbative…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Pablo Galan , Guillermo A. Mena Marugan

This study is conducted to examine the validity of generalized second law of thermodynamics (GSLT) in flat FRW for modified teleparallel gravity involving coupling between a scalar field with the torsion scalar $T$ and the boundary term…

General Relativity and Quantum Cosmology · Physics 2017-07-19 M. Zubair , Sebastian Bahamonde , Mubasher Jamil

A class of coordinate systems is found for Friedmann Cosmologies with local gravity such that it is possible to formulate quantum theory over astronomical and cosmological distances. When light from distance objects is treated as a quantum…

General Physics · Physics 2009-04-28 Charles Francis