Dark I-Love-Q

TL;DR

This paper extends the universal I-Love-Q relations, originally for neutron stars, to dark stars composed of bosonic or fermionic matter, revealing their robustness and scaling properties across different equations of state.

Contribution

It demonstrates that I-Love-Q relations apply to dark stars and explores their behavior under various equations of state and scaling symmetries.

Findings

I-Love-Q relations hold for dark stars.

Relations are consistent across different equations of state.

Scaling symmetries do not alter the I-Love-Q curves.

Abstract

For neutron stars, there exist universal relations insensitive to the equation of states, the so called I-Love-Q relations, which show the connections among the moment of inertia, tidal Love number and quadrupole moment. In this paper, we show that these relations also apply to dark stars, bosonic or fermionic. The relations can be extended to higher ranges of the variables, clarifying the deviations for dark stars in the literature, as those curves all approximate the ones generated by a polytropic equation of state, when taking the low density (pressure) limit. Besides, we find that for equation of states with scaling symmetries, the I-Love-Q curves do not change when adjusting the scaling parameters.