Formation of black holes in first-order phase transitions as a cosmological test of symmetry-breaking mechanisms

A new mechanism for the formation of black holes in a cosmological first-or der phase transition has been proposed. As soon as the walls of true-vacuum bubbles collide, their mutual penetration begins, leading to the formation of a vacuum-field configuration, so-called false-vacuum bag, whose subsequ ent collapse ends up, with a large probability, in the formation of a black hole. Observational constraints on the spectrum of primordial black holes make it possible to obtain new stringent restrictions on the parameters of the scalar potentials that determine the mechanisms of symmetry breaking in the theory of elementary particles.