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Properties of $n(\ge 5)$-dimensional static wormhole solutions are investigated in Einstein-Gauss-Bonnet gravity with or without a cosmological constant $\Lambda$. We assume that the spacetime has symmetries corresponding to the isometries…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Hideki Maeda , Masato Nozawa

We reconsider the issue of whether scalar-tensor theories can admit stable wormhole configurations supported by a non-trivial radial profile for the scalar field. Using a recently proposed effective theory for perturbations around static,…

High Energy Physics - Theory · Physics 2019-02-20 Gabriele Franciolini , Lam Hui , Riccardo Penco , Luca Santoni , Enrico Trincherini

In the context of GR, we study the thermodynamic stability of evolving Lorentzian wormholes at the apparent horizon. The average pressure of the anisotrropic components is considered as the pressure of the wormhole. According to the…

General Relativity and Quantum Cosmology · Physics 2016-07-29 S. N. Sajadi , N. Riazi

We show explicitly that traversable wormholes requiring exotic matter in 4-dimensions nevertheless have acceptable stress-tensors obeying reasonable energy conditions in higher dimensions if the wormholes are regarded as being embedded in…

General Relativity and Quantum Cosmology · Physics 2007-05-23 W. F. Kao , Chopin Soo

We discuss $(n+1)$-dimensional dynamical wormholes in an evolving cosmological background with a throat expanding with time. These solutions are examined in the general relativity framework. A linear relation between diagonal elements of an…

High Energy Physics - Theory · Physics 2014-11-20 E. Ebrahimi , N. Riazi

In this work, we consider the possibility of expanding wormholes in higher-dimensions, which is an important ingredient of modern theories of fundamental physics. An important motivation is that non-trivial topological objects such as…

General Relativity and Quantum Cosmology · Physics 2014-07-30 Mahdi Kord Zangeneh , Francisco S. N. Lobo , Nematollah Riazi

We construct simple Lagrangians of vector fields which involve second derivatives, but nevertheless lead to second order field equations. These vector fields are, therefore, analogs of generalized Galileons. Our construction is given first…

High Energy Physics - Theory · Physics 2019-07-24 Pavel Petrov

Wormholes are hypothetical shortcuts in spacetime that in General Relativity unavoidably violate all of the pointwise energy conditions. In this paper, we consider several wormhole spacetimes that, as opposed to the standard \emph{designer}…

General Relativity and Quantum Cosmology · Physics 2017-12-19 Cecilia Bejarano , Francisco S. N. Lobo , Gonzalo J. Olmo , Diego Rubiera-Garcia

We construct traversable wormholes in dilatonic Einstein-Gauss-Bonnet theory in four spacetime dimensions, without needing any form of exotic matter. We determine their domain of existence, and show that these wormholes satisfy a…

General Relativity and Quantum Cosmology · Physics 2015-05-30 Panagiota Kanti , Burkhard Kleihaus , Jutta Kunz

We have studied the stability of wormhole geometries, under massless scalar, electromagnetic and axial gravitational perturbations, in the context of higher dimensional spacetimes. Intriguingly, the construction of a wormhole spacetime in…

General Relativity and Quantum Cosmology · Physics 2022-12-13 Shauvik Biswas , Mostafizur Rahman , Sumanta Chakraborty

In [P. Kanti, B. Kleihaus, J. Kunz, Phys. Rev. Lett. 107, 271101 (2011)] it was shown that the four-dimensional Einstein-dilaton-Gauss-Bonnet theory allows for wormholes without introducing any exotic matter. The numerical solution for the…

General Relativity and Quantum Cosmology · Physics 2018-08-28 M. A. Cuyubamba , R. A. Konoplya , A. Zhidenko

We consider $f(R, T)$ theory of gravity, in which the gravitational Lagrangian is given by an arbitrary function of the Ricci scalar and the trace of the energy-momentum tensor, to study static spherically symmetric wormhole geometries…

General Relativity and Quantum Cosmology · Physics 2021-08-03 Ayan Banerjee , M. K. Jasim , Sushant G. Ghosh

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

In this paper, we construct models that admit the traversable wormhole geometries in the framework of Einstein's gravity with two scalar fields. As well known, the energy conditions are broken and we show that there appears a ghost. The…

High Energy Physics - Theory · Physics 2023-12-01 Shin'ichi Nojiri , G. G. L. Nashed

In this work, we undertake an analysis of new wormhole solutions within an action-dependent Lagrangian framework. These geometries can be traversable and supported by a positive energy density. The modification of the gravitational field…

General Relativity and Quantum Cosmology · Physics 2024-06-12 Ismael Ayuso , Ruth Lazkoz

In this work, we find novel static and spherically symmetric wormhole geometries using a three-form field. By solving the gravitational field equations, we find a variety of analytical and numerical solutions and show that it is possible…

General Relativity and Quantum Cosmology · Physics 2018-08-10 Bruno J. Barros , Francisco S. N. Lobo

We derive the simplest traversable wormhole solutions in $n$-dimensional general relativity, assuming static and spherically symmetric spacetime with a ghost scalar field. This is the generalization of the Ellis solution (or the so-called…

General Relativity and Quantum Cosmology · Physics 2015-06-17 Takashi Torii , Hisa-aki Shinkai

In the Horndeski's most general scalar-tensor theories with second-order field equations, we derive the conditions for the avoidance of ghosts and Laplacian instabilities associated with scalar, tensor, and vector perturbations in the…

General Relativity and Quantum Cosmology · Physics 2015-05-30 Antonio De Felice , Shinji Tsujikawa

We present new, asymptotically flat, static, spherically symmetric and traversable wormhole solutions in General Relativity which are supported by a family of ghost scalar fields with quartic potential. This family consists of a particular…

General Relativity and Quantum Cosmology · Physics 2019-10-31 Belen Carvente , Víctor Jaramillo , Juan Carlos Degollado , Darío Núñez , Olivier Sarbach

A multidimensional cosmological model with space-time consisting of $n (n \ge 2)$ Einstein spaces $M_{i}$ is investigated in the presence of a cosmological constant $\Lambda$ and a homogeneous minimally coupled scalar field $\varphi(t)$ as…

General Relativity and Quantum Cosmology · Physics 2009-10-22 U. Bleyer , V. D. Ivashchuk , V. N. Melnikov , A. Zhuk