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Related papers: Wormholes in Bulk Viscous Cosmology

200 papers

Ghost stars are compact configurations characterized by an arbitrarily small total mass. Such objects require regions of negative energy density -a condition typically regarded as unphysical within the context of conventional stellar…

General Relativity and Quantum Cosmology · Physics 2026-01-01 Alberto Guilabert , Ernesto Fuenmayor , Pedro Bargueño , Ernesto Contreras

This paper investigates the massive gauge field within spacetime context from a $\mathbb{Z}_2$ quotient of the constant curvature black hole. We investigate how the matter field's back reaction affects the spacetime geometry, considering…

General Relativity and Quantum Cosmology · Physics 2024-10-22 Ankit Anand , Ruben Campos Delgado , Daris Samart

Solution for a stationary spherically symmetric accretion of the relativistic perfect fluid with an equation of state p(rho) onto the Schwarzschild black hole is presented. This solution is a generalization of Michel solution and applicable…

General Relativity and Quantum Cosmology · Physics 2007-05-23 E. Babichev , V. Dokuchaev , Y. Eroshenko

While wormholes may be just as good a prediction of Einstein's theory as black holes, they are subject to severe restrictions from quantum field theory. In particular, a wormhole can only be held open by violating the null energy condition,…

General Relativity and Quantum Cosmology · Physics 2025-03-31 Peter K. F. Kuhfittig

This paper extends several previous studies of wormholes supported by two non-interacting fluids beginning with a combined model of ordinary matter and phantom dark energy with an anisotropic matter distribution. After noting that such…

General Relativity and Quantum Cosmology · Physics 2023-05-02 Peter K. F. Kuhfittig

Assuming that spacetime tunnels -wormholes and ringholes- naturally exist in the universe, we investigate the conditions making them embeddible in Friedmann space, and the possible observable effects of these tunnels, including: lensing and…

General Relativity and Quantum Cosmology · Physics 2009-10-30 Pedro F. Gonzalez-Diaz

Wormhole is defined as the topological structure with the throat connecting two asymptotically flat spaces. In order to have and maintain the structure of the wormhole, there needs the geometrical flare-out condition, i.e., the minimal size…

General Relativity and Quantum Cosmology · Physics 2015-06-15 Sung-Won Kim

Evolving Lorentzian wormholes with the required matter satisfying the Energy conditions are discussed. Several different scale factors are used and the corresponding consequences derived. The effect of extra, decaying (in time) compact…

General Relativity and Quantum Cosmology · Physics 2009-10-28 Sayan Kar , Deshdeep Sahdev

Here we shall show how to reconstruct the shape function of a spherically symmetric traversable Lorenzian wormhole near its throat if one knows high frequency quasinormal modes of the wormhole. The wormhole spacetime is given by the…

General Relativity and Quantum Cosmology · Physics 2018-07-25 R. A. Konoplya

The discovery that the Universe is undergoing an accelerated expansion has suggested the existence of an evolving equation of state. This paper discusses various wormhole solutions in a spherically symmetric spacetime with an equation of…

General Relativity and Quantum Cosmology · Physics 2011-03-15 Peter K. F. Kuhfittig

In this work, we analyze the behavior of light and matter as they pass near and through a traversable wormhole. In particular, we study the trajectories of massive and massless particles and the dust accretion around a traversable wormhole…

General Relativity and Quantum Cosmology · Physics 2023-11-15 A. Rueda , E. Contreras

It has been claimed in several papers that a phantom energy-dominated universe can undergo a ``big trip'', i.e., tunneling through a wormhole that grows faster than the cosmic substratum due to the accretion of phantom energy, and will…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Valerio Faraoni

In this work we explore the effect of rotation in the size of a traversable wormhole obtained via a double trace boundary deformation. We find that at fixed temperature the size of the wormhole increases with the angular momentum $J/M\ell$.…

High Energy Physics - Theory · Physics 2018-12-26 Elena Caceres , Anderson Seigo Misobuchi , Ming-Lei Xiao

It has been suggested that a possible candidate for the present accelerated expansion of the Universe is ''phantom energy''. The latter possesses an equation of state of the form $\omega\equiv p/\rho<-1$, consequently violating the null…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Francisco S. N. Lobo

Bulk viscosity, which characterizes the irreversible dissipative resistance of a fluid to volume changes, has been proposed as a potential mechanism for explaining both early- and late-time accelerated expansion of the Universe. In this…

Cosmology and Nongalactic Astrophysics · Physics 2025-12-18 P. P. Avelino , A. R. Gomes , D. A. Tamayo

The purpose of this paper is to show that wormholes in noncommutative geometry can be macroscopic, based in part on an earlier study. The necessary violation of the weak energy condition is attributable to the noncommutative-geometry…

General Relativity and Quantum Cosmology · Physics 2013-12-25 Peter K. F. Kuhfittig

While wormholes are as good a prediction of Einstein's theory as black holes, they are subject to severe restrictions from quantum field theory. In particular, holding a wormhole open requires a violation of the null energy condition,…

General Relativity and Quantum Cosmology · Physics 2023-05-23 Peter K. F. Kuhfittig

The paper considers the problem of the possibility of observing an accretion disk through the throat of the Ellis-Bronnikov-Morris-Thorne wormhole. It is shown that this image has a complex structure and is fundamentally different from the…

General Relativity and Quantum Cosmology · Physics 2025-08-06 I. D. Novikov , S. V. Repin , D. A. Paksivatova

The bulk viscosity of cold, dense three-flavor quark matter is studied as a function of temperature and the amplitude of density oscillations. The study is also extended to the case of two different types of anharmonic oscillations of…

Nuclear Theory · Physics 2015-03-17 Igor A. Shovkovy , Xinyang Wang

Fuzzy dark matter wormhole solutions coupled with anisotropic matter distribution are explored in higher-order curvature gravity. We derive the shape function for fuzzy wormholes and explore their possible stability. We study the embedding…

General Relativity and Quantum Cosmology · Physics 2025-06-24 Z. Yousaf , Kazuharu Bamba , Bander Almutairi , M. Z. Bhatti , M. Rizwan