Scenarios of cosmic string with variable cosmological constant

Abstract

Exact solutions of the Einstein field equations with cosmic string and space varying cosmological constant, viz., $\Lambda =\Lambda (r)$, in the energy-momentum tensors are presented. Three cases have been studied: where variable cosmological constant (1) has power law dependence, (2) is proportional to the string fluid density, and (3) is purely a constant. Some cases of interesting physical consequences have been found out such that (i) variable cosmological constant can be represented by a power law of the type $\Lambda =3r^{-2}$, (ii) variable cosmological constant and cosmic string density are interdependent to each other according to the relation $\Lambda =-8\pi {\rho }_s$, and (iii) cosmic string density can be scaled by a power law of the type ${\rho }_s=r^{-2}$. It is also shown that several known solutions can be recovered from the general form of the solutions obtained here.

15 LaTeX pages; Two new sections (Secs 4 & 5) have been included

References in corpus (16)

• Cosmological Constant - the Weight of the Vacuum
• The Case for a Positive Cosmological Lambda-term
• Discovery of a Supernova Explosion at Half the Age of the Universe and its Cosmological Implications
• The Supernova Legacy Survey: Measurement of Omega_M, Omega_Lambda and w from the First Year Data Set
• Can vacuum decay in our Universe?
• Cosmology in a String-Dominated Universe
• Dynamical dark energy or variable cosmological parameters?
• Cosmology from Rolling Massive Scalar Field on the anti-D3 Brane of de Sitter Vacua
• Nonsingular vacuum cosmologies with a variable cosmological term
• A model of the Universe including Dark Energy accounted for by both a Quintessence Field and a (negative) Cosmological Constant
• Generic Cosmic Censorship Violation in anti de Sitter Space
• Dark matter and non-Newtonian gravity from General Relativity coupled to a fluid of strings
• A fluid os strings as a viable candidate to the dark side of the universe
• Energy density in general relativity: a possible role for cosmological constant
• Acceleration field of a Universe modeled as a mixture of scalar and matter fields
• A Spacetime in Toroidal Coordinates

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