Speaker: Grigorios Panotopoulos (CENTRA)
Title: How stars challenge our view of dark matter
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 smaller scales arise. These problems may be tackled assuming a self-interacting dark matter. If dark matter is accumulated inside a star it modifies its evolution and its properties, such as mass-to-radius relations 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.
In this presentation I will present 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.