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arXiv · 0906.4520

A little inflation in the early universe at the QCD phase transition

Tillmann Boeckel·Jurgen Schaffner-Bielich
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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 10^6 - 10^8 solar masses, production of primordial magnetic fields with initial strength up to 10^12 Gauss and a gravitational wave spectrum with present day peak strain amplitude of at most h_c = 5 * 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.

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Tillmann Boeckel, Jurgen Schaffner-Bielich. 2010-06-22. A little inflation in the early universe at the QCD phase transition. https://doi.org/10.1103/physrevlett.105.041301%2010.1103%2Fphysrevlett.106.069901

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