Towards the relativistic regime of the gravothermal fluid approximation in SIDM halos

Abstract

In this work we examine the evolution of self-interacting dark matter (SIDM) halos using the gravothermal fluid approximation. The self-similar solution for the development of a halo's core presented by Balberg, Shapiro and Inagaki (2002) is analyzed along with the gravothermal collapse phase occurring subsequently in the core's evolution. Parametric models were developed in order to describe this late-stage evolution of the core, as well as computing the point in time at which the particles in the core transition into the relativistic regime of the gravothermal collapse phase and finding its relation to the SIDM cross-section.