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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

Wormholes are considered both from the Wheeler deWitt equation, as well as from the field equations in the Euclidean background of Roberson Walker mini-superspace in $R^2$ gravity. Quantum wormhole satisfies Hawking Page wormhole boundary…

General Relativity and Quantum Cosmology · Physics 2022-03-11 B Modak , Gargi Biswas

In this paper we study the possibility of sustaining an evolving wormhole via exotic matter made of phantom energy in the presence of a cosmological constant. We derive analytical evolving wormhole geometries by supposing that the radial…

General Relativity and Quantum Cosmology · Physics 2009-01-16 Mauricio Cataldo , Sergio del Campo , Paul Minning , Patricio Salgado

In this thesis, we investigate traversable wormhole spacetimes within the context of a covariant generalization of Einstein's General Relativity, namely the energy-momentum squared gravity, denoted as $f\left(R,T_{ab}T^{ab}\right)$. Here,…

General Relativity and Quantum Cosmology · Physics 2024-12-13 Nailya Ganiyeva

A static spherically symmetric wormhole solution for conformal gravity in vacuum is found. The solution possesses a single integration constant which determines the size of the neck connecting two static homogeneous universes of constant…

High Energy Physics - Theory · Physics 2009-07-08 Julio Oliva , David Tempo , Ricardo Troncoso

In this article, we study the possibility of sustaining a static and spherically symmetric traversable wormhole geometries admitting conformal motion in Einstein gravity, which presents a more systematic approach to search a relation…

General Relativity and Quantum Cosmology · Physics 2017-02-01 Piyali Bhar , Farook Rahaman , Tuhina Manna , Ayan Banerjee

Consistent dynamics which couples classical and quantum degrees of freedom exists, provided it is stochastic. This dynamics is linear in the hybrid state, completely positive and trace preserving. One application of this is to study the…

Quantum Physics · Physics 2023-01-04 Jonathan Oppenheim , Carlo Sparaciari , Barbara Šoda , Zachary Weller-Davies

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

I prove that general relativity admits no asymptotically well-behaved static spherically symmetric traversable wormholes supported by classical scalar fields and nonexotic matter. The theorem holds for all values of the scalar field…

General Relativity and Quantum Cosmology · Physics 2015-06-11 Luke M. Butcher

Noncommutative geometry, an offshoot of string theory, replaces point-like particles by smeared objects. These local effects have led to wormhole solutions in a semiclassical setting, but it has also been claimed that the noncommutative…

General Relativity and Quantum Cosmology · Physics 2024-12-24 Peter K. F. Kuhfittig

In this work we demonstrate that wormholes can in principle be naturally created during the cosmological bounce without the need for the exotic matter or any kind of additional modifications of the gravitational sector, apart from the one…

General Relativity and Quantum Cosmology · Physics 2025-02-07 Petar Pavlović , Marko Sossich

We consider a dynamical triangulation model of euclidean quantum gravity where the topology is not fixed. This model is equivalent to a tensor generalization of the matrix model of two dimensional quantum gravity. A set of moves is given…

High Energy Physics - Lattice · Physics 2009-10-22 Bas V. de Bakker

We consider the self-collision of portals in classical general relativity. Portals are wormholes supported by a single loop of negative mass cosmic string, and being wormholes, portals have a nontrivial topology. Portals can be constructed…

General Relativity and Quantum Cosmology · Physics 2021-06-15 Justin C. Feng , José P. S. Lemos , Richard A. Matzner

In this paper, we examine the existence of traversable wormhole solutions within the Chern-Simons modified gravity. We find a non-trivial solution in the theory with dynamical Chern-Simons coefficient in the absence of matter sources. This…

General Relativity and Quantum Cosmology · Physics 2018-01-10 J. R. Nascimento , A. Yu. Petrov , P. J. Porfirio

We derive a shortcut stationary metric formula for generating imperfect fluid rotating solutions, in Boyer-Lindquist coordinates, from spherically symmetric static ones. We explore the properties of the curvature scalar and stress-energy…

General Relativity and Quantum Cosmology · Physics 2014-05-12 Mustapha Azreg-Aïnou

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

We study wormhole geometries embedded in an expanding universe within a four-scalar non-linear $\sigma$ model, where the target-space metric is identified with the spacetime Ricci tensor. In this framework, wormholes can remain stable even…

General Relativity and Quantum Cosmology · Physics 2026-01-16 Taishi Katsuragawa , Shin'ichi Nojiri , Sergei D. Odintsov

The various "defect wormholes" developed by Klinkhamer have recently attracted considerable attention -- especially in view of the fact that the simplest example, the so-called "vacuum defect wormhole", was claimed to be an…

General Relativity and Quantum Cosmology · Physics 2023-10-26 Joshua Baines , Rudeep Gaur , Matt Visser

We introduce a variation of the classical Ricci flow equation that modifies the unit volume constraint of that equation to a scalar curvature constraint. The resulting equations are named the Conformal Ricci Flow Equations because of the…

Differential Geometry · Mathematics 2009-11-10 Arthur E. Fischer

We consider static spherically symmetric configurations in a Palatini extension of General Relativity including $R^2$ and Ricci-squared terms, which is known to replace the central singularity by a wormhole in the electrovacuum case. We…

High Energy Physics - Theory · Physics 2013-10-29 E. I. Guendelman , Gonzalo J. Olmo , D. Rubiera-Garcia , M. Vasihoun