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A fundamental property in wormhole physics is the flaring-out condition of the throat, which through the Einstein field equation entails the violation of the null energy condition. In the context of modified theories of gravity, it has also…

General Relativity and Quantum Cosmology · Physics 2012-11-07 Francisco S. N. Lobo

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

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

Recently, traversable wormhole geometries were constructed in the context of f(R) gravity. The latter is equivalent to a Brans-Dicke theory with a coupling parameter w=0, which is apparently excluded from the narrow interval, -3/2<w<-4/3,…

General Relativity and Quantum Cosmology · Physics 2010-05-12 Francisco S. N. Lobo , Miguel A. Oliveira

Wormholes and black holes have traditionally been treated a quite separate objects with relatively little overlap. The possibility of a connection arises in that wormholes, if they exist, might have profound influence on black holes, their…

General Relativity and Quantum Cosmology · Physics 2013-08-27 Matt Visser , David Hochberg

A basic constraint to be satisfied by Brans class I solution for being a traversible wormhole is derived. It is argued that the solution could be a wormhole analogue of the Horowitz-Ross naked black hole. It is further demonstrated that the…

General Relativity and Quantum Cosmology · Physics 2010-03-25 Amrita Bhattacharya , Ilnur Nigmatzyanov , Ramil Izmailov , Kamal K. Nandi

In this paper, we consider third order Lovelock gravity with a cosmological constant term in an n-dimensional spacetime $\mathcal{M}^{4}\times \mathcal{K}^{n-4}$, where $\mathcal{K}^{n-4} $ is a constant curvature space. We decompose the…

General Relativity and Quantum Cosmology · Physics 2015-12-23 Mahdi Kord Zangeneh , Francisco S. N. Lobo , Mohammad Hossein Dehghani

Static axisymmetric thin-shell wormholes are constructed within the framework of the Brans-Dicke scalar-tensor theory of gravity. Examples of wormholes associated with vacuum and electromagnetic fields are studied. All constructions must be…

General Relativity and Quantum Cosmology · Physics 2016-02-12 Ernesto F. Eiroa , Claudio Simeone

Wormholes that meet the flare-out condition violate the weak energy condition in classical general relativity. The purpose of this note is to show that even a slight modification of the gravitational theory could, under certain conditions,…

General Relativity and Quantum Cosmology · Physics 2017-02-03 Peter K. F. Kuhfittig

In this study, we investigate the characteristics and properties of a traversable wormhole constrained by the current astrophysical observations in the framework of modified theories of gravity (MOG). As a concrete case, we study…

General Relativity and Quantum Cosmology · Physics 2017-06-22 Deng Wang , Xin-He Meng

It is known that the formation of a wormhole typically involves a violation of the Weak Energy Condition (WEC), but the reverse is not necessarily true. In the context of Brans-Dicke gravity, the $\textit{generalized}$ Campanelli-Lousto…

General Relativity and Quantum Cosmology · Physics 2024-10-08 Hoang Ky Nguyen , Mustapha Azreg-Aïnou

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

In this paper, we explore higher-dimensional asymptotically flat wormhole geometries in the framework of Gauss-Bonnet (GB) gravity and investigate the effects of the GB term, by considering a specific radial-dependent redshift function and…

General Relativity and Quantum Cosmology · Physics 2015-04-06 Mohammad Reza Mehdizadeh , Mahdi Kord Zangeneh , Francisco S. N. Lobo

In this research work, our primary focus revolves around the examination of a specific category of traversable wormholes known as topologically charged generalized Schwarzschild-Simpson-Visser-type wormhole,…

General Relativity and Quantum Cosmology · Physics 2023-11-29 Faizuddin Ahmed

In this work we analyze traversable wormhole spacetimes in the framework of a covariant generalization of Einstein's General Relativity known as energy-momentum squared gravity, or $f\left(R,\mathcal T\right)$ gravity, where $R$ is the…

General Relativity and Quantum Cosmology · Physics 2023-11-16 João Luís Rosa , Nailya Ganiyeva , Francisco S. N. Lobo

We formulate the traversability of wormhole throats as a local and covariant null defocusing condition derived from the Raychaudhuri equation. Since unimodular gravity preserves the local geometric structure of spacetime, the null focusing…

General Relativity and Quantum Cosmology · Physics 2026-02-03 Erick Pastén , Marco Bosquez , Norman Cruz

A fundamental ingredient in wormhole physics is the flaring-out condition at the throat which, in classical general relativity, entails the violation of the null energy condition. In this work, we present the most general conditions in the…

General Relativity and Quantum Cosmology · Physics 2013-03-29 Tiberiu Harko , Francisco S. N. Lobo , M. K. Mak , Sergey V. Sushkov

Traversable wormholes in General Relativity (GR) require exotic matter sources that violate the null energy condition (NEC), and such behavior may be avoided in modified gravity. Moreover, the concept of non-commutative geometry as a…

General Relativity and Quantum Cosmology · Physics 2022-10-18 Anshuman Baruah , Parangam Goswami , Atri Deshamukhya

In this work, we investigate static and spherically symmetric traversable wormhole solutions within the framework of the extended symmetric teleparallel gravity, specifically the $\mathcal{F}(Q,\mathcal{L}_{m},\mathcal{T})$ gravity theory,…

General Relativity and Quantum Cosmology · Physics 2025-07-15 Rounak Manna , Krishna Pada Das , Ujjal Debnath

It was argued in literature that traversable wormholes can exist with arbitrarily small violation of null energy conditions. We show that if the amount of exotic material near the wormhole throat tends to zero, either this leads to a horn…

General Relativity and Quantum Cosmology · Physics 2008-11-26 O. B. Zaslavskii
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