Effect of dissipation on chromo-natural inflation

In this work, we examined chromo-natural in degrees ation 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 f in case of temperature-inflation-dependent dissipation coefficient. In case of the constant and temperature-dependent dissipation coeffient, the values of axion decay constant f can be lowered below the GUT scale.