Ricci reheating

Abstract

We present a model for viable gravitational reheating involving a scalar field directly coupled to the Ricci curvature scalar. Crucial to the model is a period of kination after inflation, which causes the Ricci scalar to change sign thus inducing a tachyonic effective mass m 2 ∝ −H 2 for the scalar field. The resulting tachyonic growth of the scalar field provides the energy for reheating, allowing for temperatures high enough for thermal leptogenesis. Additionally, the required period of kination necessarily leads to a blue-tilted primordial gravitational wave spectrum with the potential to be detected by future experiments. We find that for reheating temperatures TRH 1 GeV, the possibility exists for the Higgs field to play the role of the scalar field.

Einstein Yang–Mills Higgs dark energy revisited

“…Except for the first one, the other periods and their relative order are in agreement with the standard cosmology (see Ref. [30]); nevertheless, a kination dominated period previous to the radiation dominated one is absolutely beneficial for a successful reheating mechanism if the inflaton is only coupled to matter gravitationally [32]. Regarding the qualitative behaviour discussed in the previous section, we can conclude that, with the realistic initial conditions given by Eqs.…”

Hubble-induced phase transitions: Walls are not forever

“…The domain wall problem is consequently exorcised and replaced by a quite rich cosmological scenario. Among other interesting consequences, the temporal existence of topological defects may lead to the production of a detectable gravitational waves' background [7] even in those cases in which the amplification of the primordial spectrum of gravitational waves during kinetic domination does not lead to any observable consequence (ω 1) [28,52,53]. Our basic results can be applied to alternative symmetry breaking patterns leading to other topological defects such as strings or textures by simply replacing χ by its modulus.…”

“…This Hubble-induced spontaneous symmetry breaking (SSB), initially considered in Refs. [25][26][27] and explored by the present authors in the context of Affleck-Dine baryogenesis [24] and gravitational wave production [7], was recently advocated as a heating mechanism [28].…”

Unified early and late Universe cosmology through dissipative effects in steep quintessential inflation potential models

“…Note, however, that there are other ways of reheating the Universe in quintessential inflation and that do not rely on gravitational particle production, like instant preheating[31,32], curvaton reheating[33][34][35], Ricci reheating[36,37] and reheating with a trap[38].…”