Vacuum energy in a Friedmann-Lema�tre cosmos

Blome, Hans Joachim; Priester, Wolfgang

doi:10.1007/bf00455641

Cited by 56 publications

(39 citation statements)

References 16 publications

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“…We would like to mention that the equation of state p = −ρ (known in the literature as a false vacuum, degenerate vacuum, or ρ-vacuum [9,10,11,12]) represents a repulsive pressure. In the context of an accelerating Universe, it is argued by Usmani et al [1] that the equation of state of the kind p = −ρ may be related to the Λ-dark energy, an agent responsible for the second phase of the inflation of Hot Big Bang theory [13,14,15,16,17].…”

Section: Interior Space-timementioning

confidence: 99%

The (2+1)-dimensional gravastars

Rahaman¹,

Ray²,

Usmani³

et al. 2012

Physics Letters B

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We propose a new model of a gravastar in (2+1) anti-de Sitter space-time. This new three dimensional configuration has three different regions with different equations of state: [I] Interior: 0 ≤ r < r 1 , ρ = −p ; [II] Shell: r 1 ≤ r < r 2 , ρ = p; [III] Exterior: r 2 < r, ρ = p = 0. The outer region of this gravastar corresponds to the exterior (2 + 1) anti-de Sitter space-time, popularly known as the BTZ spacetime. Like BTZ model, Λ is taken to be negative, which at the junction turns out to be positive as required by stability of gravastar and mathematical consistency. After investigating the Interior space-time, Shell and Exterior space-time we have highlighted different physical features in terms of Length and Energy, Entropy, and Junction conditions of the spherical distribution. It is shown that the present model of charge-free gravastar in connection to the exterior (2+1) anti-de Sitter space-time or the BTZ space-time is non-singular.

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Section: Interior Space-timementioning

confidence: 99%

The (2+1)-dimensional gravastars

Rahaman¹,

Ray²,

Usmani³

et al. 2012

Physics Letters B

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“…This type of EOS in the literature is known as a 'false vacuum' or 'degenerate vacuum' or 'ρ-vacuum' [20][21][22][23]. It has been argued that, though in general this EOS leads to negative pressure, it provides easier junction conditions and a realistic expression for the mass [12][13][14]24].…”

Section: Introductionmentioning

confidence: 99%

Spherically symmetric charged compact stars

Maurya

Gupta

Ray³

et al. 2015

Eur. Phys. J. C

129

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In this article we consider the static spherically symmetric metric of embedding class 1. When solving the Einstein-Maxwell field equations we take into account the presence of ordinary baryonic matter together with the electric charge. Specific new charged stellar models are obtained where the solutions are entirely dependent on the electromagnetic field, such that the physical parameters, like density, pressure etc. do vanish for the vanishing charge. We systematically analyze altogether the three sets of Solutions I, II, and III of the stellar models for a suitable functional relation of ν(r ). However, it is observed that only the Solution I provides a physically valid and well-behaved situation, whereas the Solutions II and III are not well behaved and hence not included in the study. Thereafter it is exclusively shown that the Solution I can pass through several standard physical tests performed by us. To validate the solution set presented here a comparison has also been made with that of the compact stars, like R X J 1856 − 37, Her X − 1, P S R 1937 + 21, P S R J 1614 − 2230, and P S R J 0348 + 0432, and we have shown the feasibility of the models.

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“…This is known as the vacuum-or imperfect-fluid equation of state in the literature [20,21,22,23]. We would like to mention here that the equation of state in the form p + ρ = 0 is discussed by Gliner [32] in his study of the algebraic properties of the energymomentum tensor of ordinary matter through the metric tensors.…”

Section: Discussionmentioning

confidence: 99%

ELECTROMAGNETIC MASS IN (n + 2)-DIMENSIONAL SPACE–TIMES

Ray

2006

Int. J. Mod. Phys. D

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Einstein-Maxwell field equations correspoding to higher dimensional description of static spherically symmetric space-time have been solved under two specific set of conditions, viz., (i) ρ = 0, ν ′ = 0 and (ii) ρ = 0, ν ′ = 0 where ρ and ν represent the mass density and metric potential. The solution sets thus obtained satisfy the criteria of being electromagnetic mass model such that the gravitational mass vanishes for the vanishing charge density σ and also the space-time becomes flat. Physical features related to other parameters also have been discussed.

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Vacuum energy in a Friedmann-Lema�tre cosmos

Cited by 56 publications

References 16 publications

The (2+1)-dimensional gravastars

The (2+1)-dimensional gravastars

Spherically symmetric charged compact stars

ELECTROMAGNETIC MASS IN (n + 2)-DIMENSIONAL SPACE–TIMES

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