Dark energy cosmological models with cosmic string
In this paper we have studied the anisotropic Kantowski-Sachs, locally rotationally symmetric (LRS) Bianchi type-I and LRS Bianchi type-III geometries filled with dark energy and one dimensional cosmic string in the Saez-Ballester theory of gravitation. To get physically valid solution we take hybri...
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Veröffentlicht in: | Astrophysics and space science 2018-09, Vol.363 (9), p.1-14, Article 188 |
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Hauptverfasser: | , , , |
Format: | Artikel |
Sprache: | eng |
Schlagworte: | |
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Zusammenfassung: | In this paper we have studied the anisotropic Kantowski-Sachs, locally rotationally symmetric (LRS) Bianchi type-I and LRS Bianchi type-III geometries filled with dark energy and one dimensional cosmic string in the Saez-Ballester theory of gravitation. To get physically valid solution we take hybrid expansion law of the average scale factor which is a product of power and exponential type of functions that results in time dependent deceleration parameter (
q
). The equation of state parameter of dark energy (
ω
de
) has been discussed and we have observed that for the three models it crosses the phantom divide line (
ω
de
=
−
1
) and shows quintom like behavior. The density of dark energy (
ρ
de
) is an increasing function of redshift and remains positive throughout the evolution of the universe for the three models. Moreover in Kantowski-Sachs and LRS Bianchi type-I geometries the dark energy density dominates the string tension density (
λ
) and proper density (
ρ
) throughout the evolution of the universe. The physical and geometrical aspects of the statefinder parameters (
r
,
s
), squared speed of sound (
v
s
2
) and
ω
de
–
ω
de
′
plane are also discussed. |
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ISSN: | 0004-640X 1572-946X |
DOI: | 10.1007/s10509-018-3409-8 |