Gravity Wave Phase Shift in a Cold Quark Star with a Nonconvex QCD BZT Shock Wave Van Der Waals Equation of State

TL;DR

This paper models the internal structure of cold quark stars using a multicomponent van der Waals equation of state, revealing how phase transitions and nonconvex shock waves influence star properties and relate to astrophysical observations.

Contribution

It introduces a multicomponent van der Waals EoS to study phase transitions and BZT shock waves in quark stars, linking microscopic physics to macroscopic star characteristics.

Findings

Constraints on quark density from BZT shock conditions

Impact of phase transition on tidal deformability

Mass-radius relations consistent with high-mass neutron stars

Abstract

We investigate BZT shocks and the QCD phase transition in the dense core of a cold quark star in beta equilibrium subject to the multicomponent van der Waals (MvdW) equation of state (EoS) as a model of internal structure. When this system is expressed in terms of multiple components, it can be used to explore the impact of a phase transition from a hadronic state to a quark plasma state with a complex clustering structure. The clustering can take the form of colored diquarks or triquarks and bound colorless meson, baryon, or hyperon states at the phase transition boundary. The resulting multicomponent EoS system is nonconvex, which can give rise to Bethe-Zel'dovich-Thompson (BZT) phase changing shock waves. Using the BZT shock wave condition we find constraints on the quark density and examine how this changes the tidal deformability of the compact core. These results are then combined with the TOV equations to find the resulting mass and radius relationship. These state are compared to recent astrophysical high-mass neutron star systems, which may provide evidence for a core that has undergone a quark gluon phase transition such as PSR 0943+10 or GW 190814.