The existence of the inflationary era in the early Universe seems to be strongly supported by recent CMB observations. However, only a few realistic inflation scenarios which have close relation to particle physics seem to have been known unfortunately. The radiative neutrino mass model with inert doublet dark matter is a promising model for the present experimental issues which cannot be explained within the standard model. In order to make the model include inflation, we extend it by a complex scalar field with a specific potential. This scalar could be closely related to the neutrino mass generation at a TeV scale as well as inflation. We show that the inflation favored by the CMB observations could be realized even if inflaton takes sub-Planck values during inflation.Comment: 20 pages, 3 figure

In this work we investigate a inflationary scenario generated by a large scalar field φ that non-minimally couples to a f (R) modified gravity model. For a Starobinsky's like model, it is found that along a particular flat direction, the scalar potential takes a simpleis a non-minimal coupling to Ricci scalar R in the model. The inflation, therefore, is effectively represented as a single field inflaton scenario. For a specific example, such as a scalar potential V (φ) = µ 1 φ 2 + µ 2 φ 4 , we found that the predictions match nicely in the 1σ confidence level of Plank TT, TE, EE+lowP combination data of Planck 2015 CMB data for 0 < µ 3 ≤ 100, where µ 3 := |µ 1 |/(µ 2 M 2 p ). For example, taking µ 3 = 0.01 the scalar-to-tensor ratio r = 0.0004 and and spectral index n s = 0.96985 for N * = 50 while taking µ 3 = 100.0 produces r = 0.03 and n s = 0.96359 for N

The radiative neutrino mass model with inert doublet dark matter is a promising model for the present experimental issues which cannot be explained within the standard model.We study an extension of this model focusing on cosmological features brought about from the scalar sector. Inflation due to singlet scalars with hierarchical non-minimal couplings with the Ricci scalar may give a favorable solution for both neutrino masses and baryon number asymmetry in the Universe.