Neutron star formation with presence of hyperons

Abstract We study the influence of hyperons during the early stages of the birth of a neutron star (Kelvin-Helmholtz phase), employing neutrino opacities calculated consistently with the equation of state by considering all possible neutrino-hyperon reactions. Our results from numerical simulations of newly born neutron stars, or proto-neutron stars , show an increasingly important influence of hyperons at later times. It is remarkable the existence of metastable stars , which are stable at birth but become unstable during the evolution as the deleptonization proceeds and the hyperon concentration increases. We also present results from hydrodynamical simulations of the collapse to a black hole of metastable, hyperon-rich proto-neutron stars.