We study the influence of lepton asymmetry on the evolution of the early
Universe. The lepton asymmetry l is poorly constrained by observations and
might be orders of magnitude larger than the baryon asymmetry b, ∣l∣/b≤2×108. We find that lepton asymmetries that are large compared to the
tiny baryon asymmetry, can influence the dynamics of the QCD phase transition
significantly. The cosmic trajectory in the μB​−T phase diagram of strongly
interacting matter becomes a function of lepton (flavour) asymmetry. Large
lepton asymmetry could lead to a cosmic QCD phase transition of first order.Comment: 23 pages, 14 figures; matches published version, including Erratum.
Conclusions, pictures, numerics remained unchange