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Since the general relativistic approach requires exotic matter with negative energy density, constructing wormholes containing realistic matter is a crucial challenge. Therefore, extending General Relativity to non-minimal cases may be an…

General Relativity and Quantum Cosmology · Physics 2024-08-15 Özcan Sert

In this talk I discuss pertinence of the wormholes to the problem of circumventing the light speed barrier and present a specific class of wormholes. The wormholes of this class are static and have arbitrarily wide throats, which makes them…

General Relativity and Quantum Cosmology · Physics 2007-05-23 S. V. Krasnikov

We perform one-dimensional linear analysis and numerical simulations of the propagation of Alfven waves in a force-free magnetosphere along magnetic field lines around a spinning black hole. We use the results to investigate the dynamic…

High Energy Astrophysical Phenomena · Physics 2025-01-24 Shinji Koide , Sousuke Noda , Masaaki Takahashi

While wormholes are just as good a prediction of Einstein's theory as black holes, they are subject to severe restrictions from quantum field theory. To allow for the possibility of interstellar travel, a macroscopic wormhole would need to…

General Relativity and Quantum Cosmology · Physics 2024-09-25 Peter K. F. Kuhfittig

We argue that one can nucleate a traversable wormhole via a nonperturbative process in quantum gravity. To support this, we construct spacetimes in which there are instantons giving a finite probability for a test cosmic string to break and…

High Energy Physics - Theory · Physics 2020-01-08 Gary T. Horowitz , Don Marolf , Jorge E. Santos , Diandian Wang

Recently a bound on negative energy densities in four-dimensional Minkowski spacetime was derived for a minimally coupled, quantized, massless, scalar field in an arbitrary quantum state. The bound has the form of an uncertainty…

General Relativity and Quantum Cosmology · Physics 2009-10-28 L. H. Ford , Thomas A. Roman

A new framework is proposed for general dynamic wormholes, unifying them with black holes. Both are generically defined locally by outer trapping horizons, temporal for wormholes and spatial or null for black and white holes. Thus wormhole…

General Relativity and Quantum Cosmology · Physics 2009-10-31 Sean A. Hayward

In this article, a new family of asymptotically flat wormhole solutions in the context of symmetric teleparallel gravity, i.e., $f(Q)$ theory of gravity, are presented. Considering a power-law shape function and some different forms for…

General Relativity and Quantum Cosmology · Physics 2024-02-26 Sara Rastgoo , Foad Parsaei

It is generally agreed that the acceleration of the Universe can best be explained by the presence of dark or phantom energy. The equation of state of the latter shows that the null energy condition is violated. Such a violation is the…

General Relativity and Quantum Cosmology · Physics 2014-11-20 Mubasher Jamil , Peter K. F. Kuhfittig , Farook Rahaman , Sk. A Rakib

We construct a specific example of a class of traversable wormholes in Einstein-Dirac-Maxwell theory in four spacetime dimensions, without needing any form of exotic matter. Restricting to a model with two massive fermions in a singlet…

General Relativity and Quantum Cosmology · Physics 2021-03-15 Jose Luis Blázquez-Salcedo , Christian Knoll , Eugen Radu

This paper discusses the possible existence of traversable wormholes in f(R) modified gravity while assuming a noncommutative-geometry background, as well as zero tidal forces. The first part of the paper aims for an overview via several…

General Relativity and Quantum Cosmology · Physics 2020-07-28 Peter K. F. Kuhfittig

We perform a study to describe motion of charged particles under the influence of electromagnetic and gravitational fields of a slowly rotating wormhole with nonvanishing magnetic moment. We present analytic expression for potentials of…

General Relativity and Quantum Cosmology · Physics 2009-05-27 A. A. Abdujabbarov , B. J. Ahmedov

Morris \& Thorne \cite{morris1} proposed geometrical objects called traversable wormholes that act as bridges in connecting two spacetimes or two different points of the same spacetime. The geometrical properties of these wormholes depend…

General Relativity and Quantum Cosmology · Physics 2019-07-17 Nisha Godani , Gauranga C. Samanta

We exploit the near-horizon conformal symmetry of rapidly spinning black holes to determine universal properties of their magnetospheres. Analytic expressions are derived for the limiting form of the magnetosphere in the near-horizon…

High Energy Physics - Theory · Physics 2016-05-25 Samuel E. Gralla , Alexandru Lupsasca , Andrew Strominger

Static, spherically symmetric, traversable wormhole solutions with electric or magnetic charges are shown to exist in general relativity in the presence of scalar fields nonminimally coupled to gravity. These wormholes, however, turn out to…

General Relativity and Quantum Cosmology · Physics 2007-05-23 K. A. Bronnikov , S. Grinyok

General relativistic force-free electrodynamics is one possible plasma-limit employed to analyze energetic outflows in which strong magnetic fields are dominant over all inertial phenomena. The amazing images of black hole shadows from the…

Computational Physics · Physics 2021-03-09 J. F. Mahlmann , M. A. Aloy , V. Mewes , P. Cerdá-Durán

Several anomalies of black hole thermodynamics are resolved if one accepts hints from semi classical theory that in regions of strong gravity the energy density of the vacuum can become substantially negative. This leads to a picture of the…

General Relativity and Quantum Cosmology · Physics 2014-05-02 Werner Israel

The objective of this manuscript is to investigate the traversable wormhole solutions in the background of the $f(R, \phi)$ theory of gravity, where $R$ is the Ricci scalar and $\phi$ is the scalar potential respectively. For this reason,…

General Relativity and Quantum Cosmology · Physics 2024-04-05 Adnan Malik , Tayyaba Naz , Abdul Qadeer , M. Farasat Shamir , Z. Yousaf

In this paper we study traversable wormholes in the context of $f(R)$ gravity. Exact solutions of traversable wormholes are found by imposing the nonconstant Ricci scalar. These solutions asymptotically match spherical, flat and hyperbolic…

General Relativity and Quantum Cosmology · Physics 2019-10-23 Hanif Golchin , Mohammad Reza Mehdizadeh

The evolution of Alfven turbulence due to three-wave interactions is discussed using kinetic theory for a collisionless, thermal plasma. There are three low-frequency modes, analogous to the three modes of compressible MHD. When only Alfven…

Astrophysics · Physics 2009-11-11 Q. Luo , D. B. Melrose