How compact stars challenge our view about dark matter

TL;DR

This paper explores how the presence of bosonic dark matter inside stars affects their evolution, oscillation modes, and structure, providing new ways to constrain dark matter models through asteroseismology.

Contribution

It introduces a model of dark matter as a Bose-Einstein condensate within stars and analyzes its impact on stellar properties and oscillation modes, offering novel constraints.

Findings

Dark matter inside stars alters their mass-to-radius profiles.

Dark matter influences the frequencies of stellar oscillation modes.

The study provides bounds on dark matter properties from stellar observations.

Abstract

It is by now well established that non-relativistic matter in the Universe is dominated by dark matter, the origin and nature of which still remains a mystery. Although the collisionless dark matter paradigm works very well at large distances, a few puzzles at galactic scales arise. These problems may be tackled assuming a self-interacting dark matter. If dark matter is accumulated inside a star it will modify its evolution and its properties, such as mass-to-radius profiles and frequency oscillation modes. Asteroseismology is a relatively new, powerful tool that allows us to constrain dark matter models, offering us complementary bounds to the results coming from other means, such as collider or direct searches. I will present here the main results we have obtained assuming that the dark matter particle is a boson, which inside a star is modelled as a Bose-Einstein condensate with a polytropic equation-of-state. We have computed i) the radial and non-radial oscillation modes of light clumps of dark matter made of ultra light repulsive scalar fields, and ii) the mass-to-radius profiles as well the frequencies of radial modes of admixed dark matter strange quark stars.