Anisotropic compact star model satisfying Karmarkar conditions

• Published in: Astrophysics and space science Vol. 365; no. 2
• Main Authors: Pandya, D. M., Thakore, B., Goti, R. B., Rank, J. P., Shah, S.
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01-02-2020; Springer Nature B.V
• Subjects: Astrobiology; Astronomy; Astrophysics; Astrophysics and Astroparticles; Cosmology; Mathematical models; Observations and Techniques; Original Article; Parameters; Physics; Physics and Astronomy; Space Exploration and Astronautics; Space Sciences (including Extraterrestrial Physics; Relativistic compact stars; Anisotropy; Karmarkar condition; General relativity; Exact solutions
• ISSN: 0004-640X; 1572-946X
• DOI: 10.1007/s10509-020-3742-6

A new class of solutions describing the composition of compact stars has been proposed, assuming that the fluid distribution inside the star is anisotropic. This is achieved by assuming the appropriate metric potential and then solving Einstein’s field equations using Karmarkar conditions (Karmarkar in Proc. Indian Acad. Sci. 27:56,
1948
) to derive the expressions for star density, the radial and tangential pressures in terms of the constants
A
,
B
, a parameter ‘
a
’ and the curvature parameter
R
. The equations thus obtained have been passed through rigorous conditional analysis. It is further shown that the model is physically viable and mathematically well-behaved, fulfilling the requisite conditions viz., regularity condition, strong energy condition, causality condition, etc. Observed star candidates including EXO 1785-248, SMC X-1, SAXJ1808.43658(SS2), HER X-1, 4U 1538-52, Cen X-3 and LMC X-4 were found to conform to a good approximation through the outcome of this model for
a
=
0.5
.