Three-layered compact star in modified Buchdahl-I spatial metric with distinct equations of state

Abstract

We present a singularity free and smoothly connected complete solution for a three-layered compact star with deconfined quark matter core surrounded by coherent quantum fluid of a Bose-Einstein condensate, all enclosed under a thin envelope of a repulsive neutron-Coulomb fluid. A modified form of Buchdahl-I type spatial metric is used as a seed to obtain the explicit temporal metric potential for each layer using Einstein field equation. The process allows us to obtain insights into the pressure-density profile and associated thermodynamic properties within stellar interior, shedding light on its structural stability, mass-radius relation and physical plausibility. One of the key finding of our work is the close similarity between the M–R curve of our three-phase model star VelaX-1 and that of a strange quark star model.

Keywords

• Buchdahl-I
• Deconfined quark matter
• Bose-Einstein condensate
• Einstein field equation
• Multi-layered