Binary neutron star mergers within kaon condensation: GW170817

TL;DR

This paper investigates how kaon condensation affects the equation of state of neutron star matter and its implications for binary neutron star mergers, comparing theoretical models with GW170817 observational constraints.

Contribution

It introduces a detailed analysis of kaon condensation effects on neutron star properties using LOCV and various potentials, providing new insights into tidal deformability and maximum mass constraints.

Findings

Kaon condensation softens the EoS and reduces maximum neutron star mass.

Lower strangeness values lead to less deformed neutron stars.

Most models satisfy the GW170817 mass constraints except AV8'+TNI.

Abstract

The equation of state (EoS) of neutron star (NS) matter is investigated considering kaon condensation. Moreover, the tidal parameters related to the components of binary neutron star mergers are determined and compared to the constraints of GW170817 imposed on these quantities. In this study, we employ the lowest-order constrained variational (LOCV) approach and utilize {AV6$'$, AV8$'$, and AV18 potentials} accompanied by the three nucleon interaction (TNI) {in order to consider the nucleon-nucleon interaction}. It is known that the existence of kaons in the core of NSs softens the EoS {and thus} lowers the value of maximum mass which is expected to be greater than 2 M$_\odot$. Our results demonstrate that considering kaon condensation with a strangeness value, a$_{3}$m$_s$=-134 MeV satisfies the maximum mass constraint except for AV8$'$+TNI potential. However, the calculation of dimensionless tidal deformability shows that with the decrease of strangeness value, the neutron star gets less deformed.