Bulk viscosity of interacting magnetized strange quark matter

The bulk viscosity of interacting strange quark matter in a strong external magnetic field B-m with a real equation of state is investigated. It is found that interquark interactions can significantly increase the bulk viscosity, and the magnetic field B-m can cause irregular oscillations in both components of the bulk viscosity, zeta(parallel to) (parallel to B-m) and zeta(perpendicular to) (perpendicular to B-m). A comparison with non-interacting strange quark matter reveals that when B-m is sufficiently large, zeta(perpendicular to) is more affected by interactions than zeta(parallel to). Additionally, the quasi-oscillation of the bulk viscosity with changes in density may facilitate the formation of magnetic domains. Moreover, the resulting rmode instability windows are in good agreement with observational data for compact stars in low-mass X-ray binaries. Specifically, the r-mode instability window for interacting strange quark matter in high magnetic fields has a minimum rotation frequency exceeding 1050 Hz, which may explain the observed very high spin frequency of a pulsar with nu = 1122 Hz.

Automated summary

This study investigates the bulk viscosity of interacting strange quark matter in a strong external magnetic field. It shows that interquark interactions can greatly increase the bulk viscosity and cause irregular oscillations. The quasi-oscillation of the bulk viscosity with changes in density may facilitate the formation of magnetic domains.