Relics of the cosmological QCD phase transition

The abundance and size distribution of quark nuggets (QN's), formed a few microseconds after the big bang due to a first-order QCD phase transition in the early universe, has been estimated. It appears that stable QN's could be a viable candidate for cosmological dark matter. The evolution of baryon inhomogeneity due to evaporated (unstable) QN's is also examined.