http://arxiv.org/abs/2209.14908
We quantify the degree of fine tuning required to achieve an observationally viable period of inflation in the strongly dissipative regime of warm inflation. The “fine-tuning” parameter $\lambda$ is taken to be the ratio of the change in the height of the potential $\Delta V$ to the change in the scalar field $(\Delta \phi)^{4}$, i.e. the width of the potential, and therefore measures the requisite degree of flatness in the potential. The best motivated warm inflationary scenarios involve a dissipation rate of the kind $\Gamma\propto T^c$ with $c\geq 0$, and for all such cases, the bounds on $\lambda$ are tighter than those for standard cold inflation by at least 3 orders of magnitude. In other words, these models require an even flatter potential than standard inflation. On the other hand for the case of warm inflation with $c< 0$, we find that in a strongly dissipative regime the bound on $\lambda$ can significantly weaken with respect to cold inflation. Thus, if a warm inflation model can be constructed in a strongly dissipative, negatively temperature-dependent regime, it accommodates steeper potentials otherwise ruled out in standard inflation.
G. Montefalcone, V. Aragam, L. Visinelli, et. al.
Mon, 3 Oct 22
3/55
Comments: 6 pages, Preprint Numbers: UTWI-03-2022, NORDITA 2022-068