English
Related papers

Related papers: Looking for empty topological wormhole spacetimes …

200 papers

The huge amounts of undetected and exotic dark matter and dark energy needed to make general relativity work on large scales argue that we should investigate modifications of gravity. The only stable, metric-based and invariant alternative…

General Relativity and Quantum Cosmology · Physics 2018-07-06 R. P. Woodard

Originally proposed as a tool for teaching the general theory of relativity, wormholes are today approached in many different ways and are seeing as an efficient alternative for interstellar and time travel. Attempts to achieve…

General Relativity and Quantum Cosmology · Physics 2017-07-26 P. H. R. S. Moraes , R. A. C. Correa , R. V. Lobato

In this work, we construct time-dependent wormhole solutions in the context of $f(R)$ theory of gravity. The background matter is considered to be traceless. By considering specific shape function and power-law expansion exact solutions for…

General Physics · Physics 2014-09-09 H. Saiedi , B. Nasr Esfahani

In the presence of external, linear / nonlinear electromagnetic fields we integrate f(R) \sim R+2{\alpha}\surd(R+const.) gravity equations. In contrast to their Einsteinian cousins the obtained black holes are non-asymptotically flat with a…

General Relativity and Quantum Cosmology · Physics 2012-01-05 S. Habib Mazharimousavi , M. Halilsoy , T. Tahamtan

We investigate wormhole solutions using the modified gravity model $f(Q,T)$ with viscosity and aim to find a solution for the existence of wormholes mathematically without violating the energy conditions. We show that there is no need to…

General Relativity and Quantum Cosmology · Physics 2024-10-08 S. Davood Sadatian , S. Mohamad Reza Hosseini

In this talk I discuss pertinence of the wormholes to the problem of circumventing the light speed barrier and present a specific class of wormholes. The wormholes of this class are static and have arbitrarily wide throats, which makes them…

General Relativity and Quantum Cosmology · Physics 2007-05-23 S. V. Krasnikov

In this paper, exact asymptotically flat wormhole solutions in the context of symmetric teleparallel gravity, i.e., $f(Q)$ theory of gravity, are investigated. Since modified theories of gravity provide new field equations, we have analyzed…

General Relativity and Quantum Cosmology · Physics 2023-08-08 Foad Parsaei , Sara Rastgoo , P. K. Sahoo

Traversable wormholes, studied by Morris and Thorne \cite{Morris1} in general relativity, are investigated in this research paper in $f(R,T)$ gravity by introducing a new form of non-linear $f(R,T)$ function. By using this novel function,…

General Physics · Physics 2020-01-08 Nisha Godani , Gauranga C. Samanta

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

An intriguing solution that appears in General Relativity (GR) but has not been observed so far is the wormhole. This exotic solution describes a topological bridge connecting two distinct universes or two different points in the same…

General Relativity and Quantum Cosmology · Physics 2022-08-08 Zinnat Hassan , G. Mustafa , Joao R. L. Santos , P. K. Sahoo

This study aims to investigate the viability of a viable logarithmic f(R) gravity for inflation in giving wormhole solutions. We consider a static and spherically symmetric spacetime and two different shape functions. We found that the…

General Relativity and Quantum Cosmology · Physics 2022-06-27 Yusmantoro , Rian Julianto

We discuss simple vacuum solutions to the Einstein Equations in five dimensional space-times compactified in two different ways. In such spaces, one black hole phase and more then one black string phase may exist. Several old metrics are…

High Energy Physics - Theory · Physics 2009-11-11 Mihai Bondarescu

Wormhole solutions in General Relativity (GR) require \textit{exotic} matter sources that violate the null energy condition (NEC), and it is well known that higher-order modifications of GR and some alternative matter sources can support…

General Relativity and Quantum Cosmology · Physics 2024-03-06 Parangam Goswami , Anshuman Baruah , Atri Deshamukhya

Modifications to gravity that add additional functions of the Ricci curvature to the Einstein-Hilbert action -- collectively known as $f(R)$ theories -- have been studied in great detail. When considered as complete theories of gravity they…

Astrophysics · Physics 2009-02-20 Simon DeDeo , Dimitrios Psaltis

Models of static wormholes are investigated in the framework of $f(\textit{R}, \textit{T})$ gravity ($\textit{R}$ being the curvature scalar, and $\textit{T}$ the trace of the energy momentum tensor). An attempt to link the energy density…

General Relativity and Quantum Cosmology · Physics 2018-12-31 Emilio Elizalde , Martiros Khurshudyan

Traversable wormhole solutions in General Relativity require exotic matter sources that violate the null energy condition (NEC), and such behavior maybe avoided in modified gravity. In this study, we analyze the energy conditions for…

General Relativity and Quantum Cosmology · Physics 2023-01-25 Anshuman Baruah , Parangam Goswami , Atri Deshamukhya

Morris and Thorne \cite{morris1} proposed traversable wormholes, hypothetical connecting tools, using the concept of Einstein's general theory of relativity. In this paper, the modification of general relativity (in particular $f(R,T)$…

General Relativity and Quantum Cosmology · Physics 2020-05-05 Nisha Godani , Gauranga C. Samanta

We obtain traversable wormhole and time machine solutions of the field equations of an alternative of gravity with non-minimally curvature-matter coupling. Our solutions exhibit a non-trivial redshift function and allow for matter that…

General Relativity and Quantum Cosmology · Physics 2013-05-30 Orfeu Bertolami , Ricardo Zambujal Ferreira

We construct spherically symmetric and static solutions in $F(R)$ gravity coupled with electromagnetic fields. The solutions include new types of black holes with electric and magnetic charges. We show that the higher-derivative terms make…

General Relativity and Quantum Cosmology · Physics 2023-03-22 G. G. L. Nashed , S. Nojiri

We establish a well-posedness theory for the f(R) theory of modified gravity, which is a generalization of Einstein's theory of gravitation. The scalar curvature R of the spacetime, which arises in the integrand of the Einstein-Hilbert…

Analysis of PDEs · Mathematics 2014-12-30 Philippe G. LeFloch , Yue Ma