Speaker
Ryan Janish
(University of California, Berkeley)
Description
Dark matter that is capable of sufficiently heating a local region in a white dwarf will trigger runaway fusion and ignite a type 1a supernova. We consider dark matter (DM) candidates that heat through the production of high-energy standard model (SM) particles, and show that such particles will efficiently thermalize the white dwarf medium and ignite supernovae. Based on the existence of long-lived white dwarfs and the observed supernovae rate, we put new constraints on ultra-heavy DM candidates $m_\chi \gtrsim 10^{16}~\text{GeV}$ which produce SM particles through annihilation, decay, and DM-SM scattering in the stellar medium. As a concrete example, we rule out supersymmetric Q-ball DM in parameter space complementary to terrestrial bounds. We put further constraints on DM that is captured by white dwarfs, considering the formation and self-gravitational collapse of a DM core. For asymmetric DM, such a core may form a black hole that ignites a supernovae via Hawking radiation, and for ``almost asymmetric'' DM with non-zero but sufficiently small annihilation cross section, the core may ignite the star via a burst of annihilation during gravitational collapse. This constrains much lighter candidates, $m_\chi \gtrsim 10^{7}~\text{GeV}$. It is also intriguing that the DM-induced ignition discussed in this work provide an alternative mechanism of triggering supernovae from sub-Chandrasekhar mass progenitors.
