Bounds on sterile neutrino mixing for cosmologically interesting mass range

This talk summarizes our recent work which studied the impact of resonant ${\nu }_e\to {\nu }_s$ and ${\bar{\nu }}_e\to {\bar{\nu }}_s$ (${\nu }_s$ is a sterile neutrino) conversions on supernova physics, under the assumption that the mass of the sterile state is in the few eV -cosmologically significant range.