Zero Sound in Neutron Stars with Dense Quark Matter under Strong Magnetic Fields

TL;DR

This paper explores how strong magnetic fields in neutron stars with quark matter cores affect cooling mechanisms and zero sound stability, revealing conditions under which zero sound can facilitate star cooling.

Contribution

It introduces a detailed analysis of zero sound modes and Urca process viability in magnetized neutron star quark matter, providing new limits on effective coupling constants.

Findings

Urca process generally cannot occur in strong magnetic fields

Zero sound modes can be undamped under specific coupling conditions

Zero sound may assist in neutron star cooling processes

Abstract

We study a neutron star with a quark matter core under extremely strong magnetic fields. We investigate the possibility of an Urca process as a mechanism for the cooling of such a star. We found that apart from very particular cases, the Urca process cannot occur. We also study the stability of zero sound modes under the same conditions. We derive limits for the coupling constant of an effective theory, in order the zero sound to be undamped. We show that zero sound modes can help kinematically to facilitate a cooling process.