Effect of dissipation on chromo-natural inflation

Abstract

In this work, we examined chromo-natural inflation in the context of warm inflation with constant and variable dissipation coefficients. We studied the cosmological perturbation theory in this model and obtained the scalar and tensor power spectra in each case. The sources of density fluctuations in this model are mainly the thermal fluctuations of the inflaton field like a general warm inflationary model. Finally, cosmological observables, namely, the spectral index and tensor-to-scalar ratio are calculated. It is found that the cosmological observables are consistent with observational Planck 2018 and BICEP bounds for sub-Planckian values of axion decay constant [Formula: see text] in case of temperature–inflaton-dependent dissipation coefficient. In case of the constant and temperature-dependent dissipation coefficient, the values of axion decay constant [Formula: see text] can be lowered below the GUT scale.