Universal relations for rotating Boson Stars

TL;DR

This paper demonstrates universal relations among the moment of inertia, angular momentum, and quadrupole moment of rotating boson stars, which can distinguish them from neutron stars and aid in gravitational wave analysis.

Contribution

It establishes a universal I-chi-Q relation for rotating boson stars, differing from neutron stars, offering a new diagnostic tool for gravitational wave observations.

Findings

Universal I-chi-Q relation for boson stars

Distinct difference from neutron star relations

Potential to identify boson stars in gravitational wave data

Abstract

Boson stars represent a hypothetical exotic type of compact stellar object that may be observed from the gravitational signal of coalescing binaries in current and future GW detectors. In this work we show that the moment of inertia $I$, the (dimensionless) angular momentum $\chi$ and the quadrupole moment $Q$ of rotating boson stars obey a universal relation, valid for a wide set of boson star models. Further, the obtained $I-\chi-Q~$ relation clearly differs from its famous neutron star counterpart, providing us with an unequivocal diagnostic tool to distinguish boson stars from ordinary compact stars or other celestial bodies in GW observations. Such universal (i.e. model-independent) relations also provide a useful tool to probe the strong gravity regime of general relativity and to constrain the equation of state of matter inside compact stars.