Higgs Inflation in f(\Phi,R) Theory

Understand

We generalize the scalar-curvature coupling model ${\xi \Phi^2 R}$ of Higgs inflation to $ {\xi \Phi^a R^b} $ to study inflation.

• We compute the amplitude and spectral index of curvature perturbations generated during inflation and fix the parameters of the model by comparing these with the Planck$+$WP data.
• We find that if the scalar self coupling $\lambda$ is in the range $(10^{-5}-0.1)$, parameter $a$ in the range $(2.3 -3.6)$ and $b$ in the range $(0.77-0.22)$ at the Planck scale, one can have a viable inflation model even for $\xi \simeq 1$.
• The tensor to scalar ratio $r$ in this model is small and our model with scalar-curvature couplings is not ruled out by observational limits on $r$ unlike the pure $\frac{\lambda}{4} \Phi^4$ theory.