Gravitino dark matter, nonthermal leptogenesis, and low reheating temperature in no-scale Higgs inflation

We revisit Higgs inflation in the framework of a minimal extension of the Standard Model gauge symmetry by a U(1)(B-L) factor. Various aspects are taken into account, with particular focus on the role of the supersymmetry-breaking (SUSY) scale and the cosmological constraints associated with the gravitino. The scalar potential of the model is considered in the context of no-scale supergravity consisting of the F part constructed from the Railer function, the D terms, and soft SUSY contributions. We investigate several limiting cases and by varying the SUSY scale from a few TeV up to intermediate energies, for a spectral index around n(s) similar to 0.9655 and reheating temperature T-r <= 10(9) GeV, we find that the value of the tensor-to-scalar ratio ranges from r approximate to 10(-3) to 10(-2). Furthermore, it is shown that for certain regions of the parameter space the gravitino can live sufficiently long, and as such is a potential candidate for a dark matter component. In general, the inflationary scenario is naturally implemented and it is consistent with nonthermal leptogenesis, whereas the dominant decay channel of the inflaton yields right-handed neutrinos. Other aspects of cosmology and particle physics phenomenology are briefly discussed. Finally, we investigate the case where the inflaton is initially relaxed in a false minimum and estimate its probability to decay to the true vacuum.

Automated summary

The study revisits Higgs inflation in a minimal extension of the Standard Model, finding that the gravitino may be a potential candidate for dark matter in certain parameter regions. It also shows the effective implementation of the inflationary scenario and nonthermal leptogenesis.