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Related papers: Macroscopic wormholes in noncommutative geometry

200 papers

Wormholes are hypothetical topologically-non-trivial structures of the spacetime. From the theoretical point of view, the possibility of their existence is challenging but cannot be ruled out. This article is a compact and non-exhaustive…

General Relativity and Quantum Cosmology · Physics 2021-05-11 Cosimo Bambi , Dejan Stojkovic

This paper discusses the feasibility of thin-shell wormholes in spacetimes of embedding class one admitting a one-parameter group of conformal motions. It is shown that the surface energy density $\sigma$ is positive, while the surface…

General Relativity and Quantum Cosmology · Physics 2024-08-13 Peter K. F. Kuhfittig

Holding a Morris-Thorne wormhole open requires a violation of the null energy condition, calling for the need for so-called exotic matter near the throat. Many researchers consider exotic matter to be completely unphysical in classical…

General Relativity and Quantum Cosmology · Physics 2024-03-01 Peter K. F. Kuhfittig

We compare the effects of Noncommutative Geometry and Gravity's Rainbow on traversable wormholes which are sustained by their own gravitational quantum fluctuations. Fixing the geometry on a well tested model, we find that the final result…

General Relativity and Quantum Cosmology · Physics 2017-03-22 Remo Garattini

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

This study explores the Gaussian and the Lorentzian distributed spherically symmetric wormhole solutions in the $f(\tau, T)$ gravity. The basic idea of the Gaussian and Lorentzian noncommutative geometries emerges as the physically…

General Relativity and Quantum Cosmology · Physics 2023-01-31 G. Mustafa , Mushtaq Ahmad , Ali Övgün , M. Farasat Shamir , Ibrar Hussain

In this paper we analyze the traversability of static and evolving Schwarzschild-Anti-de Sitter wormholes. The wormhole metric under consideration is not asymptotically flat. Hence one can only embed this metric into the Euclidean space for…

General Relativity and Quantum Cosmology · Physics 2024-10-15 Sheng-Fu Zhang , Rui-Hui Lin

Traversable wormholes necessarily require violations of the averaged null energy condition; this being the definition of ``exotic matter''. However, the theorems which guarantee the energy condition violation are remarkably silent when it…

General Relativity and Quantum Cosmology · Physics 2011-07-18 Matt Visser , Sayan Kar , Naresh Dadhich

There are some gravitational theories in which the ordinary energy-momentum conservation law is not valid in the curved spacetime. Rastall gravity is one of the known theories in this regard which includes a non-minimal coupling between…

General Relativity and Quantum Cosmology · Physics 2018-04-17 H. Moradpour , N. Sadeghnezhad , S. H. Hendi

We examine the compatibility of the mirror matter concept with the non-orientable wormholes. If any particle (or classical object) is traversing through the non-orientable wormhole, it turns into a corresponding mirror particle and vice…

General Relativity and Quantum Cosmology · Physics 2014-08-04 V. I. Dokuchaev , Yu. N. Eroshenko

The paper deals with the static spherically symmetric wormhole solutions in $f(R)$-modified gravity theory with anisotropic matter field and for some particular choices for the shape functions. The present work may be considered as an…

General Relativity and Quantum Cosmology · Physics 2021-08-11 Bikram Ghosh , Saugata Mitra , Subenoy Chakraborty

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

An extended gravity theory is used to explore the possibility of non-exotic matter traversable wormholes. In the extended gravity theory, additional terms linear and quadratic in the trace of the energy momentum tensor are considered in the…

General Relativity and Quantum Cosmology · Physics 2025-09-10 S. K. Tripathy , D. Nayak , B. Mishra , D. Behera , S. K. Sahu

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

We show that non-minimal coupling between matter and geometry can indeed help in constructing stable, traversable, wormholes (WHs) without requiring exotic matter under certain conditions. In models like $f({\cal Q},{\cal T})={\cal Q}+\beta…

General Relativity and Quantum Cosmology · Physics 2025-10-02 G. G. L. Nashed , Waleed El Hanafy

We construct cylindrical, traversable wormholes with finite radii by taking into account the cut-and-paste procedure for the case of cosmic string manifolds with a positive cosmological constant. Under reasonable assumptions about the…

General Relativity and Quantum Cosmology · Physics 2013-08-14 Martín G. Richarte

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

Renormalized vacuum expectation values of electromagnetic stress-energy tensor are calculated in the background spherically-symmetrical metric of the wormhole's topology. Covariant geodesic point separation method of regularization is used.…

General Relativity and Quantum Cosmology · Physics 2009-10-22 V. Khatsymovsky

We prove the impossibility of cylindrical thin-shell wormholes supported by matter satisfying the energy conditions everywhere, under reasonable assumptions about the asymptotic behaviour of the - in general different - metrics at each side…

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

We show that the presence of a nonminimal interaction between dark matter and dark energy may lead to a violation of the null energy condition and to the formation of a configuration with nontrivial topology (a wormhole). In this it is…

General Relativity and Quantum Cosmology · Physics 2014-03-11 Vladimir Folomeev , Vladimir Dzhunushaliev