Embedding warm natural inflation in f(ϕ)T gravity

We study warm inflation in the framework of [Formula: see text] gravity, where [Formula: see text] is the inflaton and T is the trace of the energy–momentum tensor. The inflaton field is assumed to roll on the natural inflaton potential and the result is analyzed in light of Planck 2018 and BICEP/Keck 2021 data. We start by obtaining the field equations under slow-roll approximations. The scalar and tensor power spectra and their corresponding spectral index and tensor-to-scalar ratio with a temperature-dependent form of the dissipation coefficient during the inflationary era are then evaluated. It is found that the warm inflation model in [Formula: see text] gravity is compatible with observational bands.