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Fermion Mass Generation in de Sitter Space

Bjorn Garbrecht·Tomislav Prokopec
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Abstract

We study the one-loop radiative corrections for massless fermions in de Sitter space induced by a Yukawa coupling to a light, nearly minimally coupled scalar field. We show that the fermions acquire a mass. Next we construct the corresponding (nonlocal) effective fermionic action, which -- in contrast to the case of a massive Dirac fermion -- preserves chirality. Nevertheless, the resulting fermion dynamics is precisely that of a Dirac fermion with a mass proportional to the expansion rate. Our finding supports the view that an observer or a test particle responds to a scalar field in inflation by shifting its energy rather than seeing a thermal bath.

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Bjorn Garbrecht, Tomislav Prokopec. 2006-02-02. Fermion Mass Generation in de Sitter Space. https://doi.org/10.1103/physrevd.73.064036

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