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 language | English |
|---|---|
| Article number | 135004 |
| Journal | Classical and Quantum Gravity |
| Volume | 31 |
| Issue number | 13 |
| DOIs | |
| Publication status | Published - 2014 Jul 7 |
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All Science Journal Classification (ASJC) codes
- Physics and Astronomy (miscellaneous)
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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 journal › Article
TY - JOUR
T1 - Two-field inflation with non-minimal coupling
AU - Kim, Jinsu
AU - Kim, Yoonbai
AU - Park, Seong Chan
PY - 2014/7/7
Y1 - 2014/7/7
N2 - 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.
AB - 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.
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U2 - 10.1088/0264-9381/31/13/135004
DO - 10.1088/0264-9381/31/13/135004
M3 - Article
AN - SCOPUS:84902598259
VL - 31
JO - Classical and Quantum Gravity
JF - Classical and Quantum Gravity
SN - 0264-9381
IS - 13
M1 - 135004
ER -