scholarly journals Wormholes, the weak energy condition, and scalar-tensor gravity

2016 ◽  
Vol 94 (2) ◽  
Author(s):  
Rajibul Shaikh ◽  
Sayan Kar
Keyword(s):  
Energy Condition ◽  
Weak Energy Condition

scholarly journals Violation of the weak energy condition: Is it generic of spontaneous scalarization?

2004 ◽  
Vol 70 (8) ◽  
Author(s):  
Marcelo Salgado ◽  
Daniel Sudarsky ◽  
Ulises Nucamendi
Keyword(s):  
Energy Condition ◽  
Weak Energy Condition

scholarly journals KINKS, ENERGY CONDITIONS AND CLOSED TIMELIKE CURVES

2000 ◽  
Vol 09 (05) ◽  
pp. 531-541 ◽  
Author(s):  
PEDRO F. GONZÁLEZ-DÍAZ
Keyword(s):  
Energy Condition ◽  
Weak Energy Condition ◽  
Energy Conditions ◽  
Closed Timelike Curves ◽  
Causality Violation ◽  
Incoherent Radiation ◽  
Cylindrically Symmetric ◽  
Cylindrically Symmetric Spacetime ◽  
Geodesically Complete ◽  
Symmetric Spacetime

A link between the possibility of extending a geodesically incomplete kinked spacetime to a spacetime which is geodesically complete and the energy conditions is discussed for the case of a cylindrically-symmetric spacetime kink. It is concluded that neither the strong nor the weak energy condition can be satisfied in the four-dimensional example, though the latter condition may survive on the transversal sections of such a spacetime. It is also shown that the matter which propagates quantum-mechanically in a kinked spacetime can always be trapped by closed timelike curves, but signaling connections between that matter and any possible observer can only be made of totally incoherent radiation, so preventing observation of causality violation.

Closed time-like curves and weak energy condition

1997 ◽  
Vol 402 (1-2) ◽  
pp. 18-24 ◽  
Author(s):  
Y.M. Cho ◽  
D.H. Park
Keyword(s):  
Energy Condition ◽  
Weak Energy Condition

scholarly journals NONLINEAR EQUATION OF STATE, COSMIC ACCELERATION AND DECELERATION DURING PHANTOM DOMINANCE

2009 ◽  
Vol 18 (02) ◽  
pp. 329-345 ◽  
Author(s):  
S. K. SRIVASTAVA ◽  
J. DUTTA
Keyword(s):  
Equation Of State ◽  
Nonlinear Equation ◽  
Energy Condition ◽  
Phantom Energy ◽  
Weak Energy Condition ◽  
Cosmic Acceleration ◽  
Strong Energy Condition ◽  
Strong Energy ◽  
Acceleration And Deceleration ◽  
The Universe

In this paper, the RS-II model of brane gravity is considered for the phantom universe using a nonlinear equation of state. Phantom fluid is known to violate the weak energy condition. It is found that this characteristic of phantom energy is affected drastically by the negative brane tension λ of the RS-II model. It is interesting to see that up to a certain value of energy density ρ satisfying ρ/λ < 1, the weak energy condition is violated and the universe superaccelerates. But, as ρ increases more, only the strong energy condition is violated and the universe accelerates. When 1 < ρ/λ < 2, even the strong energy condition is not violated and the universe decelerates. Expansion of the universe stops when ρ = 2 λ. This is contrary to earlier results of the phantom universe exhibiting acceleration only.

scholarly journals On the Energy of a Non-Singular Black Hole Solution Satisfying the Weak Energy Condition

Universe ◽  
2020 ◽  
Vol 6 (10) ◽  
pp. 169
Author(s):  
Irina Radinschi ◽  
Theophanes Grammenos ◽  
Farook Rahaman ◽  
Marius-Mihai Cazacu ◽  
Andromahi Spanou ◽  
...  
Keyword(s):  
General Relativity ◽  
Black Hole ◽  
Energy Distribution ◽  
Black Hole Solution ◽  
Energy Condition ◽  
Weak Energy Condition ◽  
Radial Coordinate ◽  
Spherically Symmetric ◽  
Comparison Of The Results ◽  
Two Parameters

The energy-momentum localization for a new four-dimensional and spherically symmetric, charged black hole solution that through a coupling of general relativity with non-linear electrodynamics is everywhere non-singular while it satisfies the weak energy condition, is investigated. The Einstein and Møller energy-momentum complexes have been employed in order to calculate the energy distribution and the momenta for the aforesaid solution. It is found that the energy distribution depends explicitly on the mass and the charge of the black hole, on two parameters arising from the space-time geometry considered, and on the radial coordinate. Further, in both prescriptions all the momenta vanish. In addition, a comparison of the results obtained by the two energy-momentum complexes is made, whereby some limiting and particular cases are pointed out.

scholarly journals A regular scale-dependent black hole solution

2018 ◽  
Vol 27 (03) ◽  
pp. 1850032 ◽  
Author(s):  
Ernesto Contreras ◽  
Ángel Rincón ◽  
Benjamin Koch ◽  
Pedro Bargueño
Keyword(s):  
General Relativity ◽  
Black Hole ◽  
Black Hole Solution ◽  
Energy Momentum Tensor ◽  
Energy Condition ◽  
Momentum Tensor ◽  
Scale Dependence ◽  
Weak Energy Condition ◽  
Effective Energy ◽  
Regular Black Hole

In this work, we present a regular black hole solution, in the context of scale-dependent General Relativity, satisfying the weak energy condition. The source of this solution is an anisotropic effective energy–momentum tensor which appears when the scale dependence of the theory is turned-on. In this sense, the solution can be considered as a semiclassical extension of the Schwarzschild one.

GRAVITATIONAL COLLAPSE OF A SELF-INTERACTING SCALAR FIELD

2007 ◽  
Vol 22 (01) ◽  
pp. 65-74 ◽  
Author(s):  
RITUPARNO GOSWAMI ◽  
PANKAJ S. JOSHI
Keyword(s):  
Black Hole ◽  
Scalar Field ◽  
Gravitational Collapse ◽  
Energy Condition ◽  
Dynamical Evolution ◽  
Naked Singularity ◽  
Cosmic Censorship ◽  
Weak Energy Condition ◽  
Scalar Field Models ◽  
Cosmic Censorship Conjecture

We construct and study here a class of collapsing scalar field models with a nonzero potential. The weak energy condition is satisfied by the collapsing configuration and it is shown that the end state of collapse could be either a black hole or a naked singularity. It is seen that physically it is the rate of collapse that governs these outcomes of the dynamical evolution. The implications for the cosmic censorship conjecture are discussed.

scholarly journals General bounds on holographic complexity

2022 ◽  
Vol 2022 (1) ◽  
Author(s):  
Netta Engelhardt ◽  
Åsmund Folkestad
Keyword(s):  
Strong Evidence ◽  
Energy Condition ◽  
Weak Energy Condition ◽  
Positive Energy ◽  
False Vacuum ◽  
Maximal Volume ◽  
Vacuum Decay ◽  
Rigidity Result ◽  
Positive Volume ◽  
Arbitrary Dimensions

Abstract We prove a positive volume theorem for asymptotically AdS spacetimes: the maximal volume slice has nonnegative vacuum-subtracted volume, and the vacuum-subtracted volume vanishes if and only if the spacetime is identically pure AdS. Under the Complexity=Volume proposal, this constitutes a positive holographic complexity theorem. The result features a number of parallels with the positive energy theorem, including the assumption of an energy condition that excludes false vacuum decay (the AdS weak energy condition). Our proof is rigorously established in broad generality in four bulk dimensions, and we provide strong evidence in favor of a generalization to arbitrary dimensions. Our techniques also yield a holographic proof of Lloyd’s bound for a class of bulk spacetimes. We further establish a partial rigidity result for wormholes: wormholes with a given throat size are more complex than AdS-Schwarzschild with the same throat size.

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