Core-envelope model of super dense star with distinct equation of states

Abstract

The aim of the present paper is to study an anisotropic spherically symmetric core-envelope model of a super dense star in which core is equipped with linear equation of state, consistent with the quark matter while the envelope is considered to be of quadratic equation of state by adopting the philosophy of Takisa et al. (Pramana J Phys 92:40, 2019). We demonstrate that all the physical parameters are realistic within the core as well as envelope of the stellar object and continuous at the junction. Our model is shown to be physically viable and substantiate with the strange stars SAX J1808.4-3658 and 4U1608-52. Further, We infer that if the mass of the star increases then central density results to higher values and core shrinks, which justifies the dominating effect of gravity for higher mass celestial objects.

All Conformally Flat Einstein--Gauss--Bonnet static Metrics

“…We observe that the sound speed decreases from the centre outwards attaining a minimum value at the surface of the star. This could be due to phase transitions leading to different equations of state in different regions of the star [58]. should hold everywhere inside the star.…”

Linear and Riccati equations in generating functions for stellar models in general relativity

“…Anyway, its an expression for a 1 in terms of y and is a relation between the metric potentials. Quadratic EOS pr = aµ 2 + bµ + c have been used in [20], [21], [22], [23], [24]. The polytropic EOS pr = κµ 1+1/N with κ a constant and N the polytropic index was studied in [25], [26].…”

A new model for dark matter fluid sphere

“…For that reason, researchers have the curiosity to find the exact details of the internal very dense matter compositions including its density profile. Consequently, we have motivated to find the new results which represent the highly dense fluid configuration with the above DM density profile (10) by dividing the interior of the star in two regions as follows from the core envelope compact star model of R. P. Pant et al [29]. Since the negative pressure is the cause of gravitational repulsion in a region which counters the inward gravitational pull and retains the region stable against the inward gravitational attraction.…”

“…Very recent, R. P. Pant et al [29] have studied a coreenvelope model of compact star in which core is equipped with linear equation of state while the envelope is considered to be of quadratic equation of state and this work motivated us to generate a new model for stellar objects. In this work, we have proposed a new model by considering the stellar object consists of core and envelope regions.…”