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The Casimir effect for massless scalar fields satisfying Dirichlet boundary conditions on the parallel plates in the presence of one fractal extra compactified dimension is analyzed. We obtain the Casimir energy density by means of the…

High Energy Physics - Theory · Physics 2015-05-28 Hongbo Cheng

The primary objective of this article is to study the energy condition bounds for spherical and hyperbolic wormholes in well-known $f(R,T)$ theory of gravity. For this purpose, we formulate the field equations for spherically and…

General Relativity and Quantum Cosmology · Physics 2022-08-19 M. Zubair , Quratulien Muneer , Saira Waheed

Wormhole solutions, bridges that connect different parts of spacetime, were proposed early in the history of General Relativity. Soon after, it was shown that all wormholes violate classical energy conditions, which are non-negativity…

General Relativity and Quantum Cosmology · Physics 2024-07-09 Eleni-Alexandra Kontou

We study the existence and properties of wormhole throats in modified $f(R)$ gravity theory. Specifically, we concentrate on the cases where the lapse is not necessarily constant, and hence are not limited to the zero tidal force scenarios.…

General Relativity and Quantum Cosmology · Physics 2015-03-19 Andrew DeBenedictis , Dubravko Horvat

An intriguing solution that appears in General Relativity (GR) but has not been observed so far is the wormhole. This exotic solution describes a topological bridge connecting two distinct universes or two different points in the same…

General Relativity and Quantum Cosmology · Physics 2022-08-08 Zinnat Hassan , G. Mustafa , Joao R. L. Santos , P. K. Sahoo

Traversable wormholes necessarily require violations of the averaged null energy condition; this being the definition of ``exotic matter''. However, the theorems which guarantee the energy condition violation are remarkably silent when it…

General Relativity and Quantum Cosmology · Physics 2011-07-18 Matt Visser , Sayan Kar , Naresh Dadhich

Some of the simplest wormhole solutions involve massless scalar fields that take imaginary values. Massless fields can be interpreted as coupling constants in asymptotically flat or asymptotically AdS gravity theories. We argue that…

High Energy Physics - Theory · Physics 2026-05-08 Juan Maldacena , Alexander Maloney , Brian McPeak

We present non-perturbative results of the Casimir potential in non-abelian gauge theories in (2+1)D and (3+1)D for SU(2) and SU(3) in the confined and deconfined phases. For the first time, geometries beyond parallel plates in (3+1)D…

High Energy Physics - Lattice · Physics 2025-05-07 Blessed Arthur Ngwenya

In looking for imprints of extra dimensions in brane world models one usually builts these so that they are compatible with known low energy physics and thus focuses on high energy effects. Nevertheless, just as submillimeter Newton's law…

High Energy Physics - Phenomenology · Physics 2008-11-26 Roman Linares , Hugo A. Morales-Tecotl , Omar Pedraza

We describe two interesting effects in wormhole physics. First, we find that a genuinely charged matter source may appear neutral to an external observer - a phenomenon opposite to the famous Misner-Wheeler "charge without charge" effect.…

High Energy Physics - Theory · Physics 2015-05-30 Eduardo Guendelman , Alexander Kaganovich , Emil Nissimov , Svetlana Pacheva

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

Recent work in the literature had evaluated the energy-momentum tensor of a Casimir apparatus in a weak gravitational field, for an electromagnetic field subject to perfect conductor boundary conditions on parallel plates. The Casimir…

High Energy Physics - Theory · Physics 2008-11-26 Giampiero Esposito , George M. Napolitano , Luigi Rosa

Ellis-Bronnikov (EB) wormholes require violation of null energy conditions at the `throat'. This problem was cured by a simple modification of the `shape function', which introduces a new parameter $m\ge 2$ ($m=2$ corresponds to the EB…

General Relativity and Quantum Cosmology · Physics 2021-11-16 Vivek Sharma , Suman Ghosh

In quadratic gravity, the junction conditions are six and permit the appearance of double layer thin shells. Double layers arise typically in theories with dipoles, i.e., two opposite charges, such as electromagnetic theories, and appear…

General Relativity and Quantum Cosmology · Physics 2023-05-12 Joao Luís Rosa , Rui André , José P. S. Lemos

We discuss the Casimir effect for massless scalar fields subject to the Dirichlet boundary conditions on the parallel plates at finite temperature in the presence of one fractal extra compactified dimension. We obtain the Casimir energy…

High Energy Physics - Theory · Physics 2015-05-30 Hongbo Cheng

A fundamental ingredient in wormhole physics is the presence of exotic matter, which involves the violation of the null energy condition. In this context, we investigate the possibility that wormholes could be supported by quark matter at…

General Relativity and Quantum Cosmology · Physics 2014-11-13 Tiberiu Harko , Francisco S. N. Lobo , M. K. Mak

Vacuum expectation values of the field square and the energy-momentum tensor for the electromagnetic field are investigated for the geometry of a wedge with a coaxal cylindrical boundary. All boundaries are assumed to be perfectly…

High Energy Physics - Theory · Physics 2008-11-26 A. A. Saharian

Electric fields can thread a classical Einstein-Rosen bridge. Maldacena and Susskind have recently suggested that in a theory of dynamical gravity the entanglement of ordinary perturbative quanta should be viewed as creating a quantum…

High Energy Physics - Theory · Physics 2015-10-07 Dalit Engelhardt , Ben Freivogel , Nabil Iqbal

We construct cylindrical, traversable wormholes with finite radii by taking into account the cut-and-paste procedure for the case of cosmic string manifolds with a positive cosmological constant. Under reasonable assumptions about the…

General Relativity and Quantum Cosmology · Physics 2013-08-14 Martín G. Richarte

We treat the two-dimensional Achucarro-Ortiz black hole (also known as (1+1) dilatonic black hole) as a Casimir-type system. The stress tensor of a massless scalar field satisfying Dirichlet boundary conditions on two one-dimensional…

High Energy Physics - Theory · Physics 2009-11-10 Elias C. Vagenas