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arXiv · 0801.0197

A model for the very early Universe

Francesco Giacosa·Ralf Hofmann·Matthias Neubert
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Abstract

A model with N species of massless fermions interacting via (microscopic) gravitational torsion in de Sitter spacetime is investigated in the limit N->infinity. The U_V(N)*U_A(N) flavor symmetry is broken dynamically irrespective of the (positive) value of the induced four-fermion coupling. This model is equivalent to a theory with free but massive fermions fluctuating about the chiral condensate. When the fermions are integrated out in a way demonstrated long ago by Candelas and Raine, the associated gap equation together with the Friedmann equation predict that the Hubble parameter vanishes. Introducing a matter sector (subject to a finite gauge symmetry) as a source for subsequent cosmology, the neutral Goldstone field acquires mass by the chiral anomaly, resulting in a Planck-scale axion.

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Francesco Giacosa, Ralf Hofmann, Matthias Neubert. 2008-01-31. A model for the very early Universe. https://doi.org/10.1088/1126-6708%2F2008%2F02%2F077

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