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The present paper deals with some wormhole solutions which are obtained by taking two different shape functions along with zero tidal force. For obtaining wormhole solutions, anisotropic fluid and a equation of state $p_t=-\frac{a}{\rho}$…

General Relativity and Quantum Cosmology · Physics 2021-08-31 Bikram Ghosh , Saugata Mitra

The firm observational confirmation of the late-time acceleration of the universe expansion has proposed a major challenge to the theoretical foundations of cosmology and the explanation of the acceleration mechanism requires the…

General Relativity and Quantum Cosmology · Physics 2016-04-20 D Wang , Xin-He Meng

It has been suggested that the cosmological constant is a variable dynamical quantity. A class of solution has been presented for the spherically symmetric space time describing wormholes by assuming the erstwhile cosmological constant…

General Relativity and Quantum Cosmology · Physics 2008-11-26 F. Rahaman , M. Kalam , M. Sarker , A. Ghosh , B. Raychaudhuri

It has recently been shown that traversable wormholes may be supported by phantom energy. In this work phantom wormhole geometries are modelled by matching an interior traversable wormhole solution, governed by the equation of state…

General Relativity and Quantum Cosmology · Physics 2009-11-11 Francisco S. N. Lobo

We study spherically symmetric, self-similar wormhole solutions supported by colliding streams of negative-energy null dust, and their dynamical formation. Under the assumption of self-similarity, the Einstein equations reduce to a system…

General Relativity and Quantum Cosmology · Physics 2026-02-17 Yasutaka Koga , Ryota Maeda , Daiki Saito , Daisuke Yoshida

Recently, exact solutions of wormhole geometries supported by a nonminimal curvature-matter coupling were found, where the nonminimal coupling minimizes the violation of the null energy condition of normal matter at the throat. In this…

General Relativity and Quantum Cosmology · Physics 2011-03-31 Nadiezhda Montelongo Garcia , Francisco S. N. Lobo

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

There are a number of reasons to study wormholes with generic cosmological constant $\Lambda$. Recent observations indicate that present accelerating expansion of the universe demands $\Lambda>0$. On the other hand, some extended theories…

General Relativity and Quantum Cosmology · Physics 2015-11-24 Y. Heydarzade , N. Riazi , H. Moradpour

Within 2+1-dimensional cosmological new massive gravity, we consider thin-shell and thin-shell wormhole construction. For this, we introduce first, the junction conditions apt for the fourth order terms in the action of the theory. Then, by…

General Relativity and Quantum Cosmology · Physics 2019-06-04 S. Danial Forghani , S. Habib Mazharimousavi , M. Halilsoy

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 paper presents a new wormhole solution by assuming that a homogeneously distributed fluid with equation of state $p=\omega\rho$ can be adapted to an anisotropic spacetime such as a wormhole and that this spacetime admits a…

General Relativity and Quantum Cosmology · Physics 2017-07-14 Peter K. F. Kuhfittig

Spherically symmetric thin-shell wormholes in the presence of a cosmological constant are constructed applying the cut-and-paste technique implemented by Visser. Using the Darmois-Israel formalism the surface stresses, which are…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Francisco S. N. Lobo , Paulo Crawford

In the present work, we seek for static spherically symmetric solutions representing wormhole configurations in generalized Rastall gravity (GRG). In this theory, a varying coupling parameter could act as dark energy (DE) and thus, it can…

General Relativity and Quantum Cosmology · Physics 2025-04-08 Naser Sadeghnezhad

We extend the notion of phantom energy--which is generally accepted for homogeneously distributed matter with $w<-1$ in the universe--on inhomogeneous spherically symmetric spacetime configurations. A spherically symmetric distribution of…

General Relativity and Quantum Cosmology · Physics 2009-11-11 S. V. Sushkov

The gargantuan discrepancy between the value of the observed cosmological constant and that expected from the zero-point energy of known matter fields can be eliminated by supposing that on macroscopic scales the overwhelming majority of…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Enrico Rodrigo

We construct exact nonstatic nonhomogeneous spherically symmetric solutions in the theory of gravity with a scalar field possessing the exponential potential. The solution of particular interest corresponds to the scalar field with negative…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Sergey V. Sushkov , Yuan-Zhong Zhang

It has been argued that wormholes are as good a prediction of Einstein's theory as black holes but the theoretical construction requires a reverse strategy, specifying the desired geometric properties of the wormhole and leaving open the…

General Relativity and Quantum Cosmology · Physics 2017-02-15 Peter K. F. Kuhfittig

In this paper, we construct thin-shell wormholes in (2+1)-dimensions from noncommutative BTZ black hole by applying the cut-and-paste procedure implemented by Visser. We calculate the surface stresses localized at the wormhole throat by…

General Relativity and Quantum Cosmology · Physics 2016-10-31 Piyali Bhar , Ayan Banerjee

We provide a new matter source that supplies fuel to construct wormhole spacetime. The exact wormhole solutions are found in the model having, besides real matter, an anisotropic dark energy. We have shown that the exotic matters that are…

General Physics · Physics 2013-03-14 Farook Rahaman , Saibal Ray , Safiqul Islam

On general grounds, one may argue that a black hole stops radiation at the Planck mass, where the radiated energy is comparable to the black hole's mass. And also, it has been argued that there would be a "wormhole-like" structure, known as…

High Energy Physics - Theory · Physics 2015-10-21 Sung-Won Kim , Mu-In Park