Wednesday, November 18, 2009 - 3:15pm
"Is there a short inflationary period at the QCD phase transition in the early universe?"
Abstract. We explore a scenario that allows for a strong first order phase-transition of QCD at non-negligible baryon number in the early universe and its possible cosmological observable consequences. The main assumption is a quasi-stable QCD-vacuum state that leads to a short period of inflation, consequently diluting the net baryon to photon ratio to it's today observed value. A strong mechanism for baryogenesis is needed to start out with a baryon asymmetry of order unity, e.g. as provided by Affleck-Dine baryogenesis. The cosmological implications are direct effects on primordial density fluctuations up to dark matter mass scales of 1 - 10 solar masses, change in the spectral slope up to mass scales of 106 - 107 solar masses, production of primordial magnetic fields with initial strength up to 1012 Gauss and a gravitational wave spectrum with present day peak strain amplitude of at most h_c = 4.7 * 10-15 around a frequency of 4*10-8 Hz. The little QCD inflation scenario could be probed with the upcoming heavy ion research facility FAIR at GSI, Darmstadt.