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Related papers: General constraints on Horndeski wormhole throats

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We consider static spherically symmetric solutions in the scalar-tensor theory of gravity with a scalar field possessing the nonminimal kinetic coupling to the curvature. The lagrangian of the theory contains the term $(\varepsilon…

General Relativity and Quantum Cosmology · Physics 2015-06-22 R. V. Korolev , Sergey V. Sushkov

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

In this work, we investigate wormhole geometries with multiple throats and anti-throats in general relativity. The existence of these structures is identified through the analysis of minima and maxima in the area of the solution. Using…

General Relativity and Quantum Cosmology · Physics 2025-04-09 T. M. Crispim , Marcos V. de S. Silva , G. Alencar , Celio R. Muniz , Diego Sáez-Chillón Gómez

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

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

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

{\it Hunting} compact astrophysical objects such as black holes and wormholes, as well as testing gravity theories, are important issues in relativistic astrophysics. In this sense, theoretical and observational studies of quasiperiodic…

General Relativity and Quantum Cosmology · Physics 2024-03-14 Farukh Abdulkhamidov , Petya Nedkova , Javlon Rayibaev , Jutta Kunz , Bobomurat Ahmedov

This article is intended to review the recent developments in the Horndeski theory and its generalization, which provide us with a systematic understanding of scalar-tensor theories of gravity as well as a powerful tool to explore…

General Relativity and Quantum Cosmology · Physics 2019-07-22 Tsutomu Kobayashi

This article explores wormhole solutions within the framework of Finsler geometry and the modified gravity theory. Modifications in gravitational theories, such as $f(\mathcal{R}, \mathcal{T})$ gravity, propose alternatives that potentially…

General Relativity and Quantum Cosmology · Physics 2024-07-11 Yashwanth B. R. , Narasimhamurthy S. K. , Z. Nekouee

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

Recently, a modified theory of gravity was presented, which consists of the superposition of the metric Einstein-Hilbert Lagrangian with an $f(\cal R)$ term constructed \`{a} la Palatini. The theory possesses extremely interesting features…

General Relativity and Quantum Cosmology · Physics 2012-12-20 Salvatore Capozziello , Tiberiu Harko , Tomi S. Koivisto , Francisco S. N. Lobo , Gonzalo J. Olmo

Traversability in relation with tides in thin-shell wormholes is revisited to investigate the possibility of improving recently noted restrictive conditions for a safe travel across a wormhole throat. We consider wormholes mathematically…

General Relativity and Quantum Cosmology · Physics 2022-07-05 E. Rubín de Celis , C. Simeone

In this article we study a general class of non-rotating thin-shell wormholes with cylindrical symmetry. We consider two physically sound definitions of the flare-out condition and we show that the less restrictive one allows for the…

General Relativity and Quantum Cosmology · Physics 2014-10-31 Ernesto F. Eiroa , Claudio Simeone

In this work, we explore wormhole geometries in a recently proposed modified gravity theory arising from a non-conservative gravitational theory, tentatively denoted action-dependent Lagrangian theories. The generalized gravitational field…

General Relativity and Quantum Cosmology · Physics 2021-02-12 Ismael Ayuso , Francisco S. N. Lobo , José P. Mimoso

In this work, we undertake an analysis of new wormhole solutions within an action-dependent Lagrangian framework. These geometries can be traversable and supported by a positive energy density. The modification of the gravitational field…

General Relativity and Quantum Cosmology · Physics 2024-06-12 Ismael Ayuso , Ruth Lazkoz

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

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

We consider wormhole geometries subject to a gravitational action consisting of non-linear powers of the Ricci scalar. Specifically, wormhole throats are studied in the case where Einstein gravity is supplemented with a Ricci-squared and…

General Relativity and Quantum Cosmology · Physics 2007-05-23 N. Furey , A. DeBenedictis

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

The Horndeski Lagrangian brings together all possible interactions between gravity and a scalar field that yield second-order field equations in four-dimensional spacetime. As originally proposed, it only addresses phenomenology without…

General Relativity and Quantum Cosmology · Physics 2017-10-18 José Barrientos , Fabrizio Cordonier-Tello , Fernando Izaurieta , Perla Medina , Daniela Narbona , Eduardo Rodríguez , Omar Valdivia
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