Tidal Deformability of Strange Quark Planets and Strange Dwarfs

TL;DR

This paper investigates the tidal deformability of strange quark planets and dwarfs, revealing they are less deformable than normal matter counterparts, which aids in identifying such exotic objects through gravitational-wave data.

Contribution

It provides the first detailed calculations of tidal deformability for strange quark planets and dwarfs, highlighting their distinct gravitational-wave signatures.

Findings

Strange quark objects have smaller tidal deformability than normal matter counterparts.

Tidal deformability of a 0.6 M$_\odot$ strange dwarf is about 1.4 times less than a normal white dwarf.

Bare strange quark planets have extremely small tidal deformability, making them hard to distort.

Abstract

Strange quark matter, which is composed of u, d, and s quarks, could be the true ground of matter. According to this hypothesis, compact stars may actually be strange quark stars, and there may even be stable strange quark dwarfs and strange quark planets. The detection of the binary neutron star merger event GW170817 provides us new clues on the equation of state of compact stars. In this study, the tidal deformability of strange quark planets and strange quark dwarfs are calculated. It is found that the tidal deformability of strange quark objects is smaller than that of normal matter counterparts. For a typical 0.6 M$_\odot$ compact star, the tidal deformability of a strange dwarf is about 1.4 times less than that of a normal white dwarf. The difference is even more significant between strange quark planets and normal matter planets. Additionally, if the strange quark planet is a bare one (i.e., not covered by a normal matter curst), the tidal deformability will be extremely small, which means bare strange quark planets will hardly be distorted by tidal forces. Our study clearly proves the effectiveness of identifying strange quark objects via searching for strange quark planets through gravitational-wave observations.