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Related papers: Traversable wormholes in a string cloud

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We study the stability of static, spherically symmetric, traversable wormholes existing due to conformal continuations in a class of scalar-tensor theories with zero scalar field potential (so that Fisher's well-known scalar-vacuum solution…

General Relativity and Quantum Cosmology · Physics 2016-08-31 K. A. Bronnikov , S. V. Grinyok

We study radial perturbations of a wormhole in $R^2$ gravity to determine regions of stability. We also investigate massive and massless particle orbits and tidal forces in this space-time for a radially infalling observer.

General Relativity and Quantum Cosmology · Physics 2017-09-06 James B. Dent , Damien A. Easson , Thomas W. Kephart , Sara C. White

Static, spherically symmetric, traversable wormholes, induced by massless, nonminimally coupled scalar fields in general relativity, are shown to be unstable under spherically symmetric perturbations. The instability is related to…

General Relativity and Quantum Cosmology · Physics 2007-05-23 K. A. Bronnikov , S. Grinyok

Static, spherically symmetric, traversable wormhole solutions with electric or magnetic charges are shown to exist in general relativity in the presence of scalar fields nonminimally coupled to gravity. These wormholes, however, turn out to…

General Relativity and Quantum Cosmology · Physics 2007-05-23 K. A. Bronnikov , S. Grinyok

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

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

We construct a rotating thin-shell wormhole using a Myers-Perry black hole in five dimensions, using the Darmois-Israel junction conditions. The stability of the wormhole is analyzed under perturbations. We find that exotic matter is…

General Relativity and Quantum Cosmology · Physics 2016-11-04 A. Ovgun

We study a solution of Einstein's equations that describes a straight cosmic string with a variable angular deficit, starting with a $2 \pi$ deficit at the core. We show that the coordinate singularity associated to this defect can be…

General Relativity and Quantum Cosmology · Physics 2014-11-17 Rodrigo M Aros , Nelson Zamorano

Non-commutativity is a key feature of spacetime geometry. The current article explores the traversable wormhole solutions in the framework of $f(R,L_m)$ gravity within non-commutative geometry. By using the Gaussian and Lorentzian…

General Relativity and Quantum Cosmology · Physics 2023-07-10 N. S. Kavya , V. Venkatesha , G. Mustafa , P. K. Sahoo

This paper explores the effect of an extra spatial dimension on a Morris-Thorne wormhole. After proposing a suitable model, it is shown that under certain conditions, the throat of the wormhole can be threaded with ordinary matter, while…

General Relativity and Quantum Cosmology · Physics 2023-12-05 Peter K. F. Kuhfittig

Traversable wormhole are primarily useful as "gedanken-experiments" and as a theoretician's probe of the foundations of general relativity. In this work, we analyse the possibility of having tunnels in a hyperbolic spacetime. We obtain…

General Relativity and Quantum Cosmology · Physics 2010-09-02 Francisco S. N. Lobo , José P. Mimoso

We investigate the response of the traversable wormholes to the external perturbations through finding their characteristic frequencies and time-domain profiles. The considered solution describes traversable wormholes between the branes in…

General Relativity and Quantum Cosmology · Physics 2011-07-19 R. A. Konoplya , C. Molina

We construct the asymptotically flat charged thin-shell wormholes of Lovelock gravity in seven dimensions by cut-and-paste technique, and apply the generalized junction conditions in order to calculate the energy-momentum tensor of these…

General Relativity and Quantum Cosmology · Physics 2012-02-10 M. H. Dehghani , M. R. Mehdizadeh

The aim of this paper is to construct regular Hayward thin-shell wormholes and analyze their stability. We adopt Israel formalism to calculate surface stresses of the shell and check the null and weak energy conditions for the constructed…

General Relativity and Quantum Cosmology · Physics 2016-08-03 M. Sharif , Saadia Mumtaz

Thus far, the known wormholes in string theory connecting disjoint boundaries represented by finite volume quotients of hyperbolic spaces leak: they are non-perturbatively unstable towards brane-anti-brane nucleation in the flux backgrounds…

High Energy Physics - Theory · Physics 2024-04-02 Alex Buchel

A unified framework for black holes and traversible wormholes is described, where both are locally defined by outer trapping horizons, two-way traversible for wormholes and one-way traversible for black or white holes. In a two-dimensional…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Sean A. Hayward

This thesis explores traversable wormhole (WH) solutions within symmetric teleparallel gravity and its extensions, including $f(Q)$ and $f(Q, T)$ gravity. Chapter I reviews WH geometry and properties, general relativity, and modified…

General Relativity and Quantum Cosmology · Physics 2025-05-09 Moreshwar Tayde

In the string theory, the fundamental blocks of nature are not particles but one-dimensional strings. Therefore, a generalization of this idea is to think of it as a cloud of strings. Rodrigues et al. embedded the black bounces spacetime…

General Relativity and Quantum Cosmology · Physics 2023-03-17 Yi Yang , Dong Liu , Zhaoyi Xu , Zheng-Wen Long

We study linear scalar perturbations of the four-dimensional, traversable wormhole solution of Maldacena, Milekhin, and Popov(arXiv:1807.04726). The geometry is constructed by matching an asymptotically flat, near-extremal…

General Relativity and Quantum Cosmology · Physics 2025-12-01 Rajdeep Mondal , Abhishake Sadhukhan

We investigate the stability of the wormhole of the Mors-Thorne-Ellis-Bronnikov type. In our model the matter inside it consists of a radial magnetic field and an ideal phantom-fluid. Properties of the matter are described in section 1, 2…

General Relativity and Quantum Cosmology · Physics 2012-04-10 Igor Novikov , Alexander Shatskiy