The cosmic QCD transition for large lepton flavour asymmetries

Understand

We study the impact of large lepton flavour asymmetries on the cosmic QCD transition.

• Scenarios of unequal lepton flavour asymmetries are observationally almost unconstrained and therefore open up a whole new parameter space for the cosmic QCD transition.
• We find that for large asymmetries the formation of a Bose-Einstein condensate of pions can occur and identify the corresponding parameter space.
• In the vicinity of the QCD transition scale, we express the pressure in terms of a Taylor expansion with respect to the complete set of chemical potentials.