Running and running of the running of the scalar spectral index in warm inflation

Abstract

Next generation of cosmological observations are expected to improve the measurements of several quantities connected to the primordial inflation in the early Universe. These quantities include for example improved measurements for the spectral index of the scalar curvature of the primordial power spectrum and to also bring a better understanding on the scaling dependence of the primordial spectrum. This includes the running of the tilt and, possibly, also the running of the running. In this paper, we investigate the possibility of generating large runnings in the context of warm inflation. Useful analytical expressions for the runnings are derived in the context of warm inflation in the strong dissipation regime. The results are compared to and discussed for some well motivated primordial inflaton potentials that have recently been of interest in the literature.

Comments: v1:9 pages, double column, 0 figures, v2: 12 pages, double column, 0 figures. Sec 2 and 3 extended, references added, conlcusions unchanged. Version mathces the one published in Universe. This paper is an invited contribution to the Special Issue on Warm Inflation of the Universe journal