## Exploring the Parameter Space of Warm-Inflation Models

Research output: Contribution to journalArticle

### Related Edinburgh Organisations

Original language Undefined/Unknown Journal of Cosmology and Astroparticle Physics (JCAP) 10.1088/1475-7516/2015/12/046 Published - 25 Sep 2015

### Abstract

Warm inflation includes inflaton interactions with other fields throughout the inflationary epoch instead of confining such interactions to a distinct reheating era. Previous investigations have shown that, when certain constraints on the dynamics of these interactions and the resultant radiation bath are satisfied, a low-momentum-dominated dissipation coefficient $\propto T^3/m_\chi^2$ can sustain an era of inflation compatible with CMB observations. In this work, we extend these analyses by including the pole-dominated dissipation term $\propto \sqrt{m_\chi T} \exp(-m_\chi/T)$. We find that, with this enhanced dissipation, certain models, notably the quadratic hilltop potential, perform significantly better. Specifically, we can achieve 50 e-folds of inflation and a spectral index compatible with Planck data while requiring fewer mediator field ($O(10^4)$ for the quadratic hilltop potential) and smaller coupling constants, opening up interesting model-building possibilities. We also highlight the significance of the specific parametric dependence of the dissipative coefficient which could prove useful in even greater reduction in field content.

### Research areas

• hep-ph, astro-ph.CO

ID: 23475749