Testing Higgs Inflation and Its Extensions

Abstract

Amongst various inflationary models, the most phenomenologically interesting model would be the Higgs inflation. In this talk, the speaker presents possible ways to test the Higgs inflationary model and its extensions. The talk consists of mainly three parts:

(a) Possible overproduction of primordial black holes is examined in the context of the original Higgs inflationary scenario, with the inclusion of renormalisation group effects.

(b) The speaker investigates multi-field signatures of the nonminimally coupled supersymmetric Higgs inflation-type cosmological scenario, focusing on the two-field Higgs-lepton inflation model as a concrete example. This type of inflationary model is realised in a theory beyond the Standard Model embedded in supergravity with a noncanonical K\"{a}hler potential. He analyses the bispectrum of the primordial fluctuations when the inflaton trajectory deviates from a straight line, and obtains constraints on the noncanonical terms of the K\"{a}hler potential using the Planck satellite data.

(c) The speaker examines the Higgs inflation in the presence of higher-dimensional operators. In particular he introduces Ricci scalar squared term in addition to the ordinary nonminimal coupling term and test the viability of the model.