Detecting quark matter in the early universe by gravitational waves
  For large baryochemical potential, strongly interacting matter might undergo
a first order phase transition at temperatures T ~ 100-200 MeV. Within standard
cosmology, however, the chemical potential is assumed to be very small leading
to a crossover. We discuss implications of a first order QCD transition at high
chemical potential being consistent with current observations. In this
contribution we concentrate on effects on the gravitational wave spectrum.
There are other interesting cosmological signals as a modification of the power
spectrum of dark matter, the production of stellar black holes, and the seeds
for the extragalactic magnetic fields which we briefly address also.
