Two-field inflation with non-minimal coupling

Jinsu Kim, Yoonbai Kim, Seong Chan Park

Research output: Contribution to journalArticle

3 Citations (Scopus)

Abstract

Motivated by the recent 'Higgs-inflation' scenario based on a single inflaton field, we consider more generic two-field inflation with non-minimal (NM) coupling term. The generic analytic expressions are derived for cosmological observables with the product-separable as well as additive-separable potentials when the NM coupling term is dominated by one of the two fields. A hybrid model of the inflaton potential with a NM coupling , which guarantees the flatness, is closely examined as a concrete example. Compared to the minimal model with K = 0, the NM model is shown to provide better fit to the recent cosmological observation by WMAP9 and Planck2013 with the relatively lower field values during the inflationary epoch. Most interestingly, a small value of tensor-to-scalar ratio requires a large NM coupling in our scenario. The model produces non-observably small non-Gaussianity (NG) in most of parameter space while a large NG is obtainable only when the inflation takes place in a limited field space along the top of the potential.

Original languageEnglish
Article number135004
JournalClassical and Quantum Gravity
Volume31
Issue number13
DOIs
Publication statusPublished - 2014 Jul 7

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flatness
time measurement
tensors
scalars
products

All Science Journal Classification (ASJC) codes

  • Physics and Astronomy (miscellaneous)

Cite this

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Two-field inflation with non-minimal coupling. / Kim, Jinsu; Kim, Yoonbai; Park, Seong Chan.

In: Classical and Quantum Gravity, Vol. 31, No. 13, 135004, 07.07.2014.

Research output: Contribution to journalArticle

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