Neutron Stars: Laboratories for fundamental physics under extreme astrophysical conditions

TL;DR

This paper reviews the exotic matter phases in neutron stars, their theoretical modeling constrained by experiments, and explores their implications for neutron star properties and astrophysical phenomena.

Contribution

It provides a comprehensive analysis of exotic matter in neutron stars, including hyperons and Bose-Einstein condensates, and examines their effects on star stability and observable features.

Findings

Equations of state with strangeness are compatible with 2 solar mass neutron stars.

Hyperons influence the evolution and stability of protoneutron stars.

Magnetic fields affect dense matter and neutron star oscillations.

Abstract

We discuss different exotic phases and components of matter from the crust to the core of neutron stars based on theoretical models for equations of state relevant to core collapse supernova simulations and neutron star merger. Parameters of the models are constrained from laboratory experiments. It is observed that equations of state involving strangeness degrees of freedom such as hyperons and Bose-Einstein condensates are compatible with 2M$_{solar}$ neutron stars. The role of hyperons is explored on the evolution and stability of the protoneutron star (PNS) in the context of SN1987A. Moment of inertia, mass and radius which are direct probes of neutron star interior are computed and their observational consequences are discussed. We continue our study on the dense matter under strong magnetic fields and its application to magnetoelastic oscillations of neutron stars.