A roadmap to strange star

TL;DR

This paper explores the concept of strange stars, highlighting their unique properties like strong-bound surfaces and the importance of quark flavor symmetry, with the potential for identification through future multimessenger astronomy.

Contribution

It provides a pedagogical overview of strange star theory, emphasizing the role of quark interactions and surface properties in distinguishing them from neutron stars.

Findings

Strange stars have strong-bound surfaces unlike neutron stars.

Quark flavor symmetry and strong coupling are crucial in understanding strange stars.

Future multimessenger astronomy could help identify strange stars.

Abstract

What if normal baryonic matter is compressed so tightly that atomic nuclei come into close contact? This question has been asked since 1930s. The fist answer was presented by Lev Landau whose speculation has been developed, and the concept of neutron star is then popularized. However, another answer is related to strange star, which becomes worthy of attention especially after the establishment of the standard model of particle physics in 1960s. The basic ideas of this study are introduced pedagogically. We must point out emphatically that flavour symmetry of and strong coupling between quarks would be essential in seeking true answer to the question. The final answer is expected to appear in the era of multimessenger astronomy. It is emphasized too that, besides the differences of global properties (e.g., mass-radius relation, maximum mass, tidal deformability), the strong-bound surface of strange star (rather than the gravity-bound one for conventional neutron star) could play an important role in identifying a strange star by astronomical observations.