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arXiv · 1107.3739

Non-metric chaotic inflation

Kari Enqvist·Tomi Koivisto·Gerasimos Rigopoulos
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Abstract

We consider inflation within the context of what is arguably the simplest non-metric extension of Einstein gravity. There non-metricity is described by a single graviscalar field with a non-minimal kinetic coupling to the inflaton field $Ψ$, parameterized by a single parameter $γ$. We discuss the implications of non-metricity for chaotic inflation and find that it significantly alters the inflaton dynamics for field values $Ψ\gtrsim M_P/γ$, dramatically changing the qualitative behaviour in this regime. For potentials with a positive slope non-metricity imposes an upper bound on the possible number of e-folds. For chaotic inflation with a monomial potential, the spectral index and the tensor-to-scalar ratio receive small corrections dependent on the non-metricity parameter. We also argue that significant post-inflationary non-metricity may be generated.

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Kari Enqvist, Tomi Koivisto, Gerasimos Rigopoulos. 2011-07-19. Non-metric chaotic inflation. https://doi.org/10.1088/1475-7516%2F2012%2F05%2F023

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