Quintessential inflation at low reheating temperatures

Abstract

We have tested some simple quintessential inflation models, imposing the requirement that they match with the recent observational data provided by the BICEP and Planck team and leading to a reheating temperature, which is obtained via gravitational particle production after inflation, supporting the nucleosynthesis success. Moreover, for the models coming from supergravity one needs to demand low temperatures in order to avoid problems such as the gravitino overproduction or the gravitational production of moduli fields, which are obtained only when the reheating temperature is due to the production of massless particles with a coupling constant very close to its conformal value.

Reheating via gravitational particle production in the kination epoch

“…Our model is independent of such parameters and offers a numerical value to the reheating temperature. In some previous studies, where particles were created by a sudden change of metric, the authors found the reheating temperature to be much smaller, just few orders of magnitude in GeV [14,15]. In our model, where we used gravitational particle creation during the expansion of spacetime, a much higher temperature is reached.…”

“…An early stiff matter era was presumably first considered by Zel'dovich [8] and indeed, the stiff equation of state in of itself exhibits several interesting cosmological properties worth of further investigation [9,10]. Reheating in a kination epoch has received quite a bit of interest lately and numerous new studies have been done [11][12][13][14][15][16]. Most of these studies are concerned with quintessence models incorporating a period of kination and the particle production is obtained through a change of metric from de Sitter to post-inflationary metric.…”

Reheating via Gravitational Particle Production in Simple Models of Quintessence or ΛCDM Inflation

“…We point out that this kind of behavior could also be obtained by considering a universe with a small cosmological constant and by choosing a positive inflationary potential vanishing at some point, which is extended to zero for the other values of the field [14]. This comes from the fact that, when the potential is zero, the universe enters in a kination regime which lasts until the energy density of the created particles at the phase transition starts to dominate, thus matching with the current ΛCDM model, in which the square root of the cosmological constant must be of the same order as the current value of the Hubble parameter in order to take into account the cosmic coincidence.…”

The Peebles–Vilenkin quintessential inflation model revisited

“…Then, to find the accurate value of M , which depends on the reheating temperature, we have solved numerically the dynamical system (29) with initial conditions x eq and y eq at N eq = −8.121, for different values ofM , which leads to the valueH 0 = 3.53 × 10 −2 .…”

“…The introduction of the quintessential inflationary model also triggered other investigators [17,18,19,20,21,22,23,24,25,26,27,28,29,30].…”