English
Related papers

Related papers: Wormholes, the weak energy condition, and scalar-t…

200 papers

We explore the existence of Lorentzian wormholes in the context of an effective on-brane, scalar-tensor theory of gravity. In such theories, the timelike convergence condition, which is always violated for wormholes, has contributions, via…

General Relativity and Quantum Cosmology · Physics 2015-10-28 Sayan Kar , Sayantani Lahiri , Soumitra SenGupta

It is known that Lorentzian wormholes must be threaded by matter that violates the null energy condition. We phenomenologically characterize such exotic matter by a general class of microscopic scalar field Lagrangians and formulate the…

General Relativity and Quantum Cosmology · Physics 2014-11-17 C. Armendariz-Picon

We study wormhole geometries embedded in an expanding universe within a four-scalar non-linear $\sigma$ model, where the target-space metric is identified with the spacetime Ricci tensor. In this framework, wormholes can remain stable even…

General Relativity and Quantum Cosmology · Physics 2026-01-16 Taishi Katsuragawa , Shin'ichi Nojiri , Sergei D. Odintsov

Following the recent theory of Lovelock-Brans-Dicke gravity, we continue to investigate the conditions to support traversable wormholes by the gravitational effects of spacetime parity and topology, which arise from the nonminimal couplings…

General Relativity and Quantum Cosmology · Physics 2016-01-08 David Wenjie Tian

We study gravitational lensing by a class of zero Ricci scalar wormholes which arise as solutions in a scalar-tensor theory of gravity. An attempt is made to find a possible link between lensing features, stable/unstable photon orbits and…

General Relativity and Quantum Cosmology · Physics 2017-08-29 Rajibul Shaikh , Sayan Kar

In this study, we reach the equations of motion of Morris-Thorne wormhole geometry by means of the Einstein Field Equations and Klein-Gordon Equation of Scalar-Tensor theory by direct calculation. We discuss the anisotropic matter energy…

General Relativity and Quantum Cosmology · Physics 2018-07-19 Onur Genç

In this paper we attempt to examine the possibility of construction of a traversable wormhole on the Randall-Sundrum braneworld with ordinary matter employing the Kuchowicz potential as one of the metric potentials. In this scenario, the…

General Relativity and Quantum Cosmology · Physics 2022-03-31 Rikpratik Sengupta , Shounak Ghosh , Mehedi Kalam , Saibal Ray

In this work, we analyse the evolution of time-dependent traversable wormhole geometries in a Friedmann-Lema\^{i}tre-Robertson-Walker background in the context of the scalar-tensor representation of hybrid metric-Palatini gravity. We deduce…

General Relativity and Quantum Cosmology · Physics 2021-04-06 Mahdi Kord Zangeneh , Francisco S. N. Lobo

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

We explore the properties of traversable wormhole spacetimes within the framework of energy-momentum squared gravity, also known as $f(R,T^2)$ gravity, where $R$ represents the Ricci scalar, $T_{ab}$ is the energy-momentum tensor, and $T^2…

General Relativity and Quantum Cosmology · Physics 2025-02-27 Nailya Ganiyeva , João Luís Rosa , Francisco S. N. Lobo

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

Morris \& Thorne \cite{morris1} proposed geometrical objects called traversable wormholes that act as bridges in connecting two spacetimes or two different points of the same spacetime. The geometrical properties of these wormholes depend…

General Relativity and Quantum Cosmology · Physics 2019-07-17 Nisha Godani , Gauranga C. Samanta

We consider $f(R, T)$ theory of gravity, in which the gravitational Lagrangian is given by an arbitrary function of the Ricci scalar and the trace of the energy-momentum tensor, to study static spherically symmetric wormhole geometries…

General Relativity and Quantum Cosmology · Physics 2021-08-03 Ayan Banerjee , M. K. Jasim , Sushant G. Ghosh

The study of traversable wormholes is very hot topic for the past 30 years. One of the best possible way to make traversable wormhole is using the thin-shells to cut and paste two spacetime which has tunnel from one region of space-time to…

General Relativity and Quantum Cosmology · Physics 2016-10-27 Ali Övgün

It is proved that all thin-shell wormholes built from two identical regions of vacuum static, spherically symmetric space-times have a negative shell surface energy density in any scalar-tensor theory of gravity with a non-ghost massless…

General Relativity and Quantum Cosmology · Physics 2009-07-22 Kirill A. Bronnikov , Alexei A. Starobinsky

The static spherically symmetric traversable wormholes are analysed in the Einstein- Cartan theory of gravitation. In particular, we computed the torsion tensor for matter fields with different spin S = 0; 1/2; 1; 3/2. Interestingly, only…

General Relativity and Quantum Cosmology · Physics 2018-01-12 Emmanuele Battista , Elisabetta Di Grezia , Mattia Manfredonia , Gennaro Miele

In this paper, we evaluate traversable wormhole solutions through Karmarkar condition in $f(R,T)$ theory, where $T$ is the trace of the energy-momentum tensor and $R$ represents the Ricci scalar. We develop a wormhole shape function for the…

General Relativity and Quantum Cosmology · Physics 2023-03-06 M. Sharif , Arooj Fatima

In this work, we construct traversable wormhole geometries in the context of f(R) modified theories of gravity. We impose that the matter threading the wormhole satisfies the energy conditions, so that it is the effective stress-energy…

General Relativity and Quantum Cosmology · Physics 2009-11-12 Francisco S. N. Lobo , Miguel A. Oliveira

The solutions of traversable wormholes and their geometries are investigated in higher-curvature gravity with boundary terms for each case under the presence of anisotropic, isotropic and barotropic fluids in detail. For each case, the…

General Relativity and Quantum Cosmology · Physics 2023-10-03 M. Ilyas , Kazuharu Bamba

We study wormhole solutions in the framework of f (R,T) gravity where R is the scalar curvature, and T is the trace of the stress-energy tensor of the matter. We have obtained the shape function of the wormhole by specifying an equation of…

General Relativity and Quantum Cosmology · Physics 2014-01-30 Tahereh Azizi
‹ Prev 1 2 3 10 Next ›