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Related papers: Wormhole Thermodynamics at Apparent Horizons

200 papers

This paper discusses the feasibility of thin-shell wormholes in spacetimes of embedding class one admitting a one-parameter group of conformal motions. It is shown that the surface energy density $\sigma$ is positive, while the surface…

General Relativity and Quantum Cosmology · Physics 2024-08-13 Peter K. F. Kuhfittig

A spacetime horizon comprising with a black hole singularity acts like a boundary of a thermal system associated with the notions of temperature and entropy. In case of static metric of BTZ black hole, the field equations near horizon…

High Energy Physics - Theory · Physics 2008-11-26 M. Akbar

We explore thermodynamics of the apparent horizon in $f(T)$ gravity with both equilibrium and non-equilibrium descriptions. We find the same dual equilibrium/non-equilibrium formulation for $f(T)$ as for $f(R)$ gravity. In particular, we…

General Relativity and Quantum Cosmology · Physics 2015-05-30 Kazuharu Bamba , Chao-Qiang Geng

In this paper, we study the thermodynamical properties of the (2+1)dimensional black hole with a Coulomb-like electric field and the differential form of the first law of thermodynamics is derived considering a virtual displacement of its…

General Relativity and Quantum Cosmology · Physics 2012-11-07 Alexis Larranaga , Luz Angela Garcia

The properties of an hyperbolically-expanding wormhole are studied. Using a particular equation of state for the fluid on the wormhole throat, we reached an equation of motion for the throat that leads to a constant surface energy density…

General Relativity and Quantum Cosmology · Physics 2019-06-21 Hristu Culetu

The primary objective of this article is to study the energy condition bounds for spherical and hyperbolic wormholes in well-known $f(R,T)$ theory of gravity. For this purpose, we formulate the field equations for spherically and…

General Relativity and Quantum Cosmology · Physics 2022-08-19 M. Zubair , Quratulien Muneer , Saira Waheed

We investigated the regular multi-horizon black holes in the Einstein gravity, $F(R)$ gravity and the 5 dimensional Gauss-Bonnet gravity, all of them coupled with non-linear electrodynamics. We presented several explicit examples of the…

High Energy Physics - Theory · Physics 2017-11-22 Shin'ichi Nojiri , S. D. Odintsov

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

Traversable wormholes have traditionally been viewed as intrinsically topological entities in some multiply connected spacetime. Here, we show that topology is too limited a tool to accurately characterize a generic traversable wormhole: in…

General Relativity and Quantum Cosmology · Physics 2011-09-30 David Hochberg , Matt Visser

A spherically symmetric wormhole in Newtonian gravitation in curved space, enhanced with a connection between the mass density and the Ricci scalar, is presented. The wormhole, consisting of two connected asymptotically flat regions,…

General Relativity and Quantum Cosmology · Physics 2016-03-23 Paulo Luz , José P. S. Lemos

It is well known that a C-field, generated by a certain source equation leads to interesting changes in the cosmological solutions of Einstein's equations. In this article we present and analyze a simple Lorentzian vacuum wormhole in the…

General Relativity and Quantum Cosmology · Physics 2010-11-11 F. Rahaman , B. C. Bhui , P. Ghosh

It has been suggested that the cosmological constant is a variable dynamical quantity. A class of solution has been presented for the spherically symmetric space time describing wormholes by assuming the erstwhile cosmological constant…

General Relativity and Quantum Cosmology · Physics 2008-11-26 F. Rahaman , M. Kalam , M. Sarker , A. Ghosh , B. Raychaudhuri

The metric of some Lorentzian wormholes in the background of the FRW universe is obtained. It is shown that for a de Sitter space-time the new solution is supported by Phantom Energy. The wave equation for a scalar field in such backgrounds…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Behrouz Mirza , Mehdi Eshaghi , Shahram Dehdashti

In this work, we analyze the wormhole solutions in $f(R)$ gravity. Specifically we sought for wormhole geometry solutions for the following three shape functions: (i) $b(r)=r_{0}+\rho_{0}r_{0}^{3}\ln\left(\frac{r_{0}}{r}\right)$, (ii)…

General Relativity and Quantum Cosmology · Physics 2022-04-22 B. Mishra , A. S. Agrawal , S. K. Tripathy , S. Ray

In this thesis, we investigate traversable wormhole spacetimes within the context of a covariant generalization of Einstein's General Relativity, namely the energy-momentum squared gravity, denoted as $f\left(R,T_{ab}T^{ab}\right)$. Here,…

General Relativity and Quantum Cosmology · Physics 2024-12-13 Nailya Ganiyeva

In this paper we first obtain Friedmann equations for the $(n-1)$-dimensional brane embedded in the $(n+1)$-dimensional bulk, with intrinsic curvature term of the brane included in the action (DGP model). Then, we show that one can always…

High Energy Physics - Theory · Physics 2008-11-26 Ahmad Sheykhi , Bin Wang , Rong-Gen Cai

Wormholes are speculative structures linking disparate space-time points. Their geometry can be obtained by solving Einstein equations with tolerating the violation of null energy conditions. Recently, many researchers have studied…

General Relativity and Quantum Cosmology · Physics 2022-03-10 J. Sadeghi , B. Pourhassan , S. Noori Gashti , S. Upadhyay

We present $n(\ge 4)$-dimensional planar black holes and wormholes with a flat exterior, which are originated by an exact solution in general relativity. The nonvacuum regions of these objects are described by the extended dynamical region…

General Relativity and Quantum Cosmology · Physics 2025-10-17 Hideki Maeda , Cristian Martinez

This paper discusses a new wormhole solution that admits conformal motion, given a noncommutative-geometry background. After a discussion of the wormhole geometry and the energy conditions, the analysis proceeds with the calculation of the…

General Physics · Physics 2015-06-16 Farook Rahaman , Saibal Ray , G. S. Khadekar , P. K. F. Kuhfittig , Indrani Karar

We obtain a large class of Lorentzian wormhole spacetimes in scalar-tensor gravity, for which the matter stress energy does satisfy the weak energy condition. Our constructions have zero Ricci scalar and an everywhere finite, non-zero…

General Relativity and Quantum Cosmology · Physics 2016-07-12 Rajibul Shaikh , Sayan Kar