Talk (non-conference) (Invited)

PUBDB-2020-03545

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Harmonic Hybrid Inflation

Welling, Y. M. (Corresponding author)DESY* ; Westphal, A.DESY* ; Righi, N.DESY* ; Carta, F.DESY*

2020

Abstract: We present a mechanism for realizing hybrid inflation using two axion fields with a purely non-perturbatively generated scalar potential. The structure of scalar potential is highly constrained by the discrete shift symmetries of the axions. We show that harmonic hybrid inflation generates observationally viable slow-roll inflation for a wide range of initial conditions. This is possible while accommodating certain UV arguments favoring constraints f≲MP and Δϕ60≲MP on the axion periodicity and slow-roll field range, respectively. We discuss controlled ℤ2-symmetry breaking of the adjacent axion vacua as a means of avoiding cosmological domain wall problems. Including a minimal form of ℤ2-symmetry breaking into the minimally tuned setup leads to a prediction of primordial tensor modes with the tensor-to-scalar ratio in the range 10−4≲r≲0.01, directly accessible to upcoming CMB observations. Finally, we outline several avenues towards realizing harmonic hybrid inflation in type IIB string theory.

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Contributing Institute(s):

1. Theorie-Gruppe (T)

Research Program(s):

1. 611 - Fundamental Particles and Forces (POF3-611) (POF3-611)

Experiment(s):

1. No specific instrument

Appears in the scientific report 2020

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