Shear oscillations in the hadron-quark mixed phase

TL;DR

This paper investigates shear oscillations in the hadron-quark mixed phase within neutron stars, showing that oscillation frequencies are strongly influenced by surface tension, which can be estimated through stellar observations.

Contribution

It provides the first evaluation of shear modulus in the hadron-quark mixed phase and links shear oscillation frequencies to surface tension, enabling potential observational estimates.

Findings

Shear oscillation frequencies depend strongly on surface tension.

Fundamental frequencies are nearly proportional to surface tension at fixed stellar mass.

Observation of stellar oscillations can help estimate surface tension values.

Abstract

Inside neutron stars, the hadron-quark mixed phase is expected during the first order phase transition from the hadron phase to the quark phase. The geometrical structure of the mixed phase strongly depends on the surface tension at the hadron-quark interface. We evaluate the shear modulus which is one of the specific properties of the hadron-quark mixed phase. As an application, we study shear oscillations due to the hadron-quark mixed phase in neutron stars. We find that the frequencies of shear oscillations depend strongly on the surface tension; with a fixed stellar mass, the fundamental frequencies are almost proportional to the surface tension. Thus, one can estimate the value of surface tension via the observation of stellar oscillations with the help of the information on the stellar mass.