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Related papers: Energetics in Condensate Star and Wormholes

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Static observers remain on Killing-vector world lines and measure the rest-mass+kinetic energies of particles moving past them, and the flux of that mechanical energy through space and time. The total mechanical energy is the total flux…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Joseph Katz , Donald Lynden-Bell , Jiri Bicak

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

In this work, we find exact wormhole solutions in the context of noncommutative geometry, and further explore their physical properties and characteristics. The energy density of these wormhole geometries is a smeared and particle-like…

General Relativity and Quantum Cosmology · Physics 2008-12-23 Remo Garattini , Francisco S. N. Lobo

We consider generalized energy conditions in modified theories of gravity by taking into account the further degrees of freedom related to scalar fields and curvature invariants. The latter are usually recast as generalized {\it geometrical…

General Relativity and Quantum Cosmology · Physics 2014-02-14 Salvatore Capozziello , Francisco S. N. Lobo , José P. Mimoso

It has been shown that t00 component of the energy-momentum pseudotensor in the case of cylindrically symmetrical static gravitational field cannot be interpreted as energy density of the gravitation field. An approach has been suggested…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Roald Sosnovskiy

The current study explores the generalized embedded wormhole solutions in the background of $f(\mathcal{R},\mathcal{G})$ gravity, where $\mathcal{R}$ represents the Ricci scalar and $\mathcal{G}$ denotes the Gauss-Bonnet invariant. To…

General Relativity and Quantum Cosmology · Physics 2023-04-14 Asifa Ashraf , Saadia Mumtaz , Faisal Javed , Zhiyue Zhang

This review summarizes the current status of the energy conditions in general relativity and quantum field theory. We provide a historical review and a summary of technical results and applications, complemented with a few new derivations…

General Relativity and Quantum Cosmology · Physics 2020-06-08 Eleni-Alexandra Kontou , Ko Sanders

We consider the nonlinear energy conditions and their quantum extensions. These new energy conditions behave much better than the usual pointwise energy conditions in the presence of semiclassical quantum effects. Analogous quantum…

General Relativity and Quantum Cosmology · Physics 2015-05-20 Prado Martin-Moruno

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 first review the various definition of the total energy in the gravitational system. The naive definition has some defects, and we review how to modify the definition of the total energy. Then we explicitly demonstrate how to calculate…

General Relativity and Quantum Cosmology · Physics 2007-05-23 M. Kenmoku , K. Shigemoto

This essay reviews some of the recent progress in the area of energy conditions and wormholes. Most of the discussion centers on the subject of ``quantum inequality'' restrictions on negative energy. These are bounds on the magnitude and…

General Relativity and Quantum Cosmology · Physics 2016-11-09 Thomas A. Roman

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

In this paper, we review the issue of defining energy for test particles on a background stationary spacetime. We revisit the different notions of energy as defined by different observers. As is well known, the existence of a time-like…

General Relativity and Quantum Cosmology · Physics 2015-09-08 Alejandro Corichi

We consider stationary, cylindrically symmetric configurations in general relativity and formulate necessary conditions for the existence of rotating cylindrical wormholes. It is shown that in a comoving reference frame the rotational part…

General Relativity and Quantum Cosmology · Physics 2013-09-12 Kirill A. Bronnikov , Vladimir G. Krechet , José P. S. Lemos

In GR the static gravitational potential of a self-gravitating body goes as 1/r at large distances and any slower decrease leads to infinity energy. We show that in a class of four-dimensional massive gravity theories there exists…

High Energy Physics - Theory · Physics 2013-05-29 Denis Comelli , Marco Crisostomi , Fabrizio Nesti , Luigi Pilo

Traversable wormholes in General Relativity (GR) require exotic matter sources that violate the null energy condition (NEC), and such behavior may be avoided in modified gravity. Moreover, the concept of non-commutative geometry as a…

General Relativity and Quantum Cosmology · Physics 2022-10-18 Anshuman Baruah , Parangam Goswami , Atri Deshamukhya

We have examined the possible construction of a stationary, spherically symmetric and spatially inhomogeneous wormhole spacetime supported by the phantom energy. The later is supposed to be represented by the modified Chaplygin gas equation…

General Relativity and Quantum Cosmology · Physics 2009-03-27 Mubasher Jamil , M. Umar Farooq , Muneer Ahmad Rashid

It is known that traversible wormholes require negative energy density. We here argue how much negative energy is needed for wormholes, using a local analysis which does not assume any symmetry. and in particular allows dynamic…

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

The energy density of asymptotically flat gravitational fields can be calculated from a simple expression involving the trace of the torsion tensor. Integration of this energy density over the whole space yields the ADM energy. Such…

General Relativity and Quantum Cosmology · Physics 2009-10-28 J. W. Maluf , A. Kneip

In this work, we explore the possibility that static and spherically symmetric traversable wormhole geometries are supported by modified teleparallel gravity or f(T) gravity, where T is the torsion scalar. Considering the field equations…

General Relativity and Quantum Cosmology · Physics 2012-02-16 Christian G. Boehmer , Tiberiu Harko , Francisco S. N. Lobo