Quark Nuggets as Baryonic Dark Matter

Abstract

The cosmic first-order phase transition from quarks to hadrons, occurring a few microseconds after the big bang, would lead to the formation of quark nuggets which would be stable on a cosmological timescale if the associated baryon number was larger than a critical value. We examine the possibility that these surviving quark nuggets may not only be viable candidates for cold dark matter but could even close the universe.