English
Related papers

Related papers: Wormholes supported by two non-interacting fluids

200 papers

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

This current analysis offers novel wormhole solutions in the background of newly developed extended $f(\mathcal{R},\mathcal{L}_m)$ gravity. We use an anisotropic matter source and a particular type of energy density demonstrating cold dark…

General Relativity and Quantum Cosmology · Physics 2024-03-05 G. Mustafa , Faisal Javed , S. K. Maurya , M. Govender , Amna Saleem

Exact solutions of traversable wormholes are found under the assumption of spherical symmetry and the existence of a {\it non-static} conformal symmetry, which presents a more systematic approach in searching for exact wormhole solutions.…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Christian G. Boehmer , Tiberiu Harko , Francisco S. N. Lobo

Morris and Thorne developed wormhole solutions in the late 1980s when they discovered a recipe that wormholes must follow for travelers to cross them safely. They describe exotic matter as satisfying $-p_{r} > \rho$, where $p_{r}$ is the…

General Relativity and Quantum Cosmology · Physics 2024-06-25 P. H. R. S. Moraes , A. S. Agrawal , B. Mishra

A wormhole is constructed by cutting and joining two spacetimes satisfying the low energy string equations with a dilaton field. In spacetimes described by the "string metric" the dilaton energy-momentum tensor need not satisfy the weak or…

General Relativity and Quantum Cosmology · Physics 2010-11-19 Dan N. Vollick

We construct and analyse wormhole solutions in quantised space-time. The field equations are constructed from the deformed wormhole metric in the proper reference frame using tetrads. The spatial geometry of the wormhole is analysed in the…

General Relativity and Quantum Cosmology · Physics 2025-01-28 Harsha Sreekumar , E. Harikumar

We present a traversable-wormhole solution of the gravitational field equation of General Relativity without need of exotic matter (exotic matter can, for example, have negative energy density and vanishing isotropic pressure). Instead of…

General Relativity and Quantum Cosmology · Physics 2023-06-16 F. R. Klinkhamer

A fundamental ingredient in wormhole physics is the presence of exotic matter, which involves the violation of the null energy condition. Although a plethora of wormhole solutions have been explored in the literature, it is useful to find…

General Relativity and Quantum Cosmology · Physics 2015-05-28 Nadiezhda Montelongo Garcia , Francisco S. N. Lobo

Wormholes allowed by the general theory of relativity that are simultaneously traversable by humanoid travelers are subject to severe constraints from quantum field theory, particularly the so-called quantum inequalities, here slightly…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Peter K. F. Kuhfittig

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

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

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

We study the geometry of a wormhole spacetime filled with anisotropic matter in the context of general relativity. In the course of the study, new static and spherically symmetric solutions, analytic and numerical ones, are found. We…

General Relativity and Quantum Cosmology · Physics 2019-09-04 Hyeong-Chan Kim , Youngone Lee

For a generic $f(R)$ which admits a polynomial expansion of at least third order (i.e. $\frac{d^{3}f}{dR^{3}}\neq 0$) we find the near-throat wormhole solution. Necessary conditions for the existence of wormholes in such $f(R)$ theories are…

General Relativity and Quantum Cosmology · Physics 2016-11-15 S. Habib Mazharimousavi , M. Halilsoy

It was argued in literature that traversable wormholes can exist with arbitrarily small violation of null energy conditions. We show that if the amount of exotic material near the wormhole throat tends to zero, either this leads to a horn…

General Relativity and Quantum Cosmology · Physics 2008-11-26 O. B. Zaslavskii

We consider novel wormhole solutions supported by a matter content that minimally violates the null energy condition. More specifically, we consider an equation of state in which the sum of the energy density and radial pressure is…

General Relativity and Quantum Cosmology · Physics 2014-11-10 Mariam Bouhmadi-Lopez , Francisco S. N. Lobo , Prado Martin-Moruno

A possible candidate for the late time accelerated expanding Universe is phantom energy, which possesses rather bizarre properties, such as the prediction of a Big Rip singularity and the violation of the null energy condition. The latter…

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

Recent papers by Fewster and Roman have emphasized that wormholes supported by arbitrarily small amounts of exotic matter will have to be incredibly fine-tuned if they are to be traversable. This paper discusses a wormhole model that…

General Relativity and Quantum Cosmology · Physics 2009-11-11 Peter K. F. Kuhfittig

Wormhole geometries in curvature-matter coupled modified gravity are explored, by considering an explicit nonminimal coupling between an arbitrary function of the scalar curvature, R, and the Lagrangian density of matter. It is the…

General Relativity and Quantum Cosmology · Physics 2010-11-09 Nadiezhda Montelongo Garcia , Francisco S. N. Lobo

In this work, wormholes, tunnel like structures introduced by Morris \& Thorne \cite{Morris95}, are explored within the framework of $f(R)$ gravity. Using the shape function $b(r)=r_0\big(\frac{r}{r_0}\big)^\gamma$, where $0<\gamma<1$, and…

General Relativity and Quantum Cosmology · Physics 2019-08-14 Gauranga C Samanta , Nisha Godani