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In this study, both the evolution of wormholes (by examining both the energy conditions and using the TOV equations) and the effects of the Karmarkar condition on the solutions obtained under certain specific cases were examined in the…

General Relativity and Quantum Cosmology · Physics 2025-06-04 Murat Metehan Turkoglu

The well-known problem of wormholes in general relativity (GR) is the necessity of exotic matter, violating the Weak Energy Condition (WEC), for their support. This problem looks easier if, instead of island-like configurations, one…

General Relativity and Quantum Cosmology · Physics 2020-01-08 K. A. Bronnikov , S. V. Bolokhov , M. V. Skvortsova

Spherically symmetric thin-shell wormholes are constructed within the framework of Brans-Dicke gravity. It is shown that, for appropriate values of the Brans-Dicke constant, these wormholes can be supported by matter satisfying the energy…

General Relativity and Quantum Cosmology · Physics 2009-06-26 Ernesto F. Eiroa , Martin G. Richarte , Claudio Simeone

The quartic self-interacting conformal scalar field is used to construct a thin-shell wormhole satisfying all energy conditions. Accompanying the scalar field is the extremal Reissner-Nordstr\"om black hole with a positive cosmological…

General Relativity and Quantum Cosmology · Physics 2020-03-31 S. Danial Forghani , S. Habib Mazharimousavi , Mustafa Halilsoy

In this paper we study the traversability of a wormhole in the context of Asymptotically Safe Gravity (ASG) for two different cases, namely, the spherical case and the pseudospherical case. We carried out an analysis in the throat of the…

General Relativity and Quantum Cosmology · Physics 2022-04-28 M. Nilton , J. Furtado , G. Alencar

We construct a new type of thin-shell wormhole for non-asymptotically flat charged black holes in generalized dilaton-axion gravity inspired by low-energy string theory using cut-and-paste technique. We have shown that this thin shell…

General Relativity and Quantum Cosmology · Physics 2015-06-05 Ayan Banerjee , Farook Rahaman , Surajit Chattopadhyay , Sumita Banerjee

In this work we propose the modelling of static wormholes within the $f(R,T)$ extended theory of gravity perspective. We present some models of wormholes, which are constructed from different hypothesis for their matter content, i.e.,…

General Relativity and Quantum Cosmology · Physics 2017-09-06 P. H. R. S. Moraes , P. K. Sahoo

We construct models of two exotic objects: (i) a wormhole whose throat is hidden by a stellar object like a neutron star; and (ii) a wormhole inside a black hole. We work within Einstein's gravity coupled to two scalar fields with a…

General Relativity and Quantum Cosmology · Physics 2024-04-08 Shin'ichi Nojiri , S. D. Odintsov , Vladimir Folomeev

Recent studies relating the approximations for the equations of state for thin shells and their consequent perturbative evolution are extended to thin-shell wormholes in theories beyond general relativity and more than four spacetime…

General Relativity and Quantum Cosmology · Physics 2018-01-10 Emilio Rubín de Celis , Cecilia Tomasini , Claudio Simeone

We discuss how the assumption of variable equation of state (EoS) allows the elimination of the instability at equilibrium throat radius $a_0=3M$ featured by previous Schwarzschild thin-shell wormhole models. Unobstructed stability regions…

General Relativity and Quantum Cosmology · Physics 2015-08-19 Victor Varela

Recently, spherically symmetric, static wormholes supported by exotic dust and a radial magnetic field have been derived and argued to be stable with respect to linear radial fluctuations. In this report we point out that these wormholes…

General Relativity and Quantum Cosmology · Physics 2010-04-06 Olivier Sarbach , Thomas Zannias

In this paper we construct charged thin-shell wormholes in (2+1)-dimensions applying the cut-and -paste technique implemented by Visser, from a BTZ black hole which was discovered by Banados, Teitelboim and Zanelli, and the surface stress…

General Relativity and Quantum Cosmology · Physics 2013-10-23 Ayan Banerjee

In this paper we seek a relationship between the assumption of conformal symmetry and the exotic matter needed to hold a wormhole open. By starting with a Morris-Thorne wormhole having a constant energy density, it is shown that the…

General Relativity and Quantum Cosmology · Physics 2024-02-20 Peter K. F. Kuhfittig

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

For an arbitrary Tolman wormhole, unconstrained by symmetry, we shall define the bounce in terms of a three-dimensional edgeless achronal spacelike hypersurface of minimal volume. (Zero trace for the extrinsic curvature plus a "flare-out"…

General Relativity and Quantum Cosmology · Physics 2009-10-31 David Hochberg , Carmen Molina-Paris , Matt Visser

We construct solutions of plane symmetric wormholes in the presence of a negative cosmological constant by matching an interior spacetime to the exterior anti-de Sitter vacuum solution. The spatial topology of this plane symmetric wormhole…

General Relativity and Quantum Cosmology · Physics 2009-11-10 José P. S. Lemos , Francisco S. N. Lobo

The present paper is intended for studying the effect of strong gravitational lensing in the context of charged wormhole. To study this effect, the conditions determining the existence of photon spheres at and outside the throat are…

General Relativity and Quantum Cosmology · Physics 2021-06-02 Nisha Godani , Gauranga C. Samanta

This paper extends an earlier study by the author [Phys. Rev. D, vol. 98, 064041 (2018), arXiv:1809.01993] in several significant ways. To begin with, the extra spatial dimension is assumed to be time dependent, while the redshift and shape…

General Relativity and Quantum Cosmology · Physics 2023-12-06 Peter K. F. Kuhfittig

Thin-shell wormholes are constructed starting from the exotic branch of Wiltshire spherically symmetric solution of Einstein-Gauss-Bonnet gravity. The energy-momentum tensor of the shell is studied, and it is shown that configurations…

General Relativity and Quantum Cosmology · Physics 2012-03-19 Claudio Simeone

A fundamental property of Morris-Thorne wormholes is the so-called flare-out condition that automatically results in a violation of the null energy condition (NEC) in classical general relativity. By contrast, in $f(R)$ modified gravity,…

General Relativity and Quantum Cosmology · Physics 2020-08-20 Peter K. F. Kuhfittig
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