%0 Generic
%A Boeckel, Moritz Tillmann
%D 2011
%F heidok:12104
%K Gravitationswellen , Strukturbildung , Baryogenese , Dunkle MateriePhase Transition , Quantum Chromodynamics , Cosmology , Dark Matter , Structure Formation
%R 10.11588/heidok.00012104
%T A Little Inflation at the Cosmological QCD Phase Transition
%U https://archiv.ub.uni-heidelberg.de/volltextserver/12104/
%X In this thesis I explore a new scenario that allows for a strong first order phasetransition of quantum chromodynamics (QCD) at non-negligible baryon density in the early universe and its possible observable consequences. After an introduction to important aspects of the underlying fields of QCD and cosmology I discuss the possibility of a short inflationary phase at the cosmological QCD phase transition. 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 which is also discussed within the thesis. The second main assumption for this ”little inflation” scenario is a quasistable QCD-vacuum state that leads to a short period of exponential expansion consequently diluting the net baryon to photon ratio to today’s observed value. The cosmological implications are among other things direct effects on primordial density fluctuations up to length scales corresponding to an enclosed dark matter mass of  1 M⊙, change in the spectral slope up to 10^6 M⊙, production of strong primordial magnetic fields and a gravitational wave spectrum that could be observed by future pulsar timing gravitational wave detectors.