Solving the $η$-Problem in Hybrid Inflation with Heisenberg Symmetry and Stabilized Modulus

Antusch, Stefan; Bastero-Gil, Mar; Dutta, Koushik; King, Steve F.; Kostka, Philipp M.

Solving the $η$-Problem in Hybrid Inflation with Heisenberg Symmetry and Stabilized Modulus

Authors

Description

We propose a class of models in which the $η$-problem of supersymmetric hybrid inflation is resolved using a Heisenberg symmetry, where the associated modulus field is stabilized and made heavy with the help of the large vacuum energy during inflation without any fine-tuning. The proposed class of models is well motivated both from string theory considerations, since it includes the commonly encountered case of no-scale supergravity Kaehler potential, and from the perspective of particle physics since a natural candidate for the inflaton in this class of models is the right-handed sneutrino which is massless during the inflationary epoch, and subsequently acquires a large mass at the end of inflation. We study a specific example motivated by sneutrino hybrid inflation with no-scale supergravity in some detail, and show that the spectral index may lie within the latest WMAP range, while the tensor-to-scalar ratio is very small.
27 pages, 4 figures; appendix and reference added; version published in JCAP