Anisotropic strange stars in Tolman–Kuchowicz spacetime

Abstract

We attempt to study a singularity-free model for the spherically symmetric anisotropic strange stars under Einstein's general theory of relativity by exploiting the Tolman-Kuchowicz (Tolman in Phys Rev 55:364, 1939; Kuchowicz in Acta Phys Pol 33:541, 1968) metric. Further, we have assumed that the cosmological constant Λ is a scalar variable dependent on the spatial coordinate r . To describe the strange star candidates we have considered that they are made of strange quark matter distribution, which is assumed to be governed by the MIT bag equation of state. To obtain unknown constants of the stellar system we match the interior Tolman-Kuchowicz metric to the exterior modified Schwarzschild metric with the cosmological constant, at the surface of the system. Following Deb et al. (Ann Phys 387:239, 2017) we have predicted the exact values of the radii for different strange star candidates based on the observed values of the masses of the stellar objects and the chosen parametric values of the Λ as well as the bag constant B. The set of solutions satisfies all the physical requirements to represent strange stars. Interestingly, our study reveals that as the values of the Λ and B increase the anisotropic system become gradually smaller in size turning the whole system into a more compact ultra-dense stellar object.

Anisotropic relativistic fluid spheres: an embedding class I approach

“…(ω r = p r /ρ) and (ω t = p t /ρ) are less than 1, proving Zeldovich's condition is satisfies everywhere inside the compact object. Furthermore, in Table 1 we have shown the possible values of the physical parameters a, A and B using parameters values of the compact star SAX J1808.4-3658 with mass Table 2 shows that the central energy density is within this range, which is in complete agreement with many other reported results in the literature [45][46][47][48][49][50][51][52][53][54][55][57][58][59][60][61][63][64][65][66][67][68][69][70][71][72][73][74][75][76][77][78][79][80]. Figure 6 clearly shows that our stellar system fulfills all the energy conditions which are a basic condition for a compact astrophysical structure to be physically acceptable.…”

Influence of strong magnetic field on the structure properties of strange quark stars

“…Also, the maximum value of Z s in our calculations (for the case of density-dependent bag constant using Set B) is about 16.47% lower than the upper bound of that for the subluminal EOS (Z CL s = 0.85) [61]. As expected, the values of the surface redshift of SQS is larger than that for the results of neutron stars [62]. The surface redshift of a neutron star is reported in a range of 0.49 -0.56 in [63].…”

Charged anisotropic strange stars in general relativity

“…where λ(r ) = ln(1 + a r 2 + b r 4 ), and ν = 2h r 2 + lnC, (2) being a, b, h and C constants parameters and the above metric potentials describe as a Tolman-Kuchowicz (TK) metric [1,2,67]. However, these constants will be fixed by physical requirements of the solution.…”