Speaker
Description
Many proposed self-interacting dark matter (SIDM) models give rise to radiative processes that can dissipate energy from dark matter halos. We present the first extension of the N-body formalism for frequent small-angle self-interactions (fSIDM) that includes effective dissipation.
We find that dissipation qualitatively changes the gravothermal evolution of SIDM halos beyond simply accelerating collapse. Sufficiently strong central cooling can invert the usual role of heat conduction: the formation of an isothermal core is suppressed such that conduction remains directed inward throughout the evolution. Meanwhile, outer halo regions can cool efficiently, leading to enhanced mass infall and distinct final density profiles. These effects depend strongly on the cooling rate but are comparatively insensitive to the angular dependence of the self-interaction cross section.
Our results reveal new dynamical behavior of dissipative SIDM and open a route to connecting halo structure and recently reported dark compact objects to dark-sector microphysics.