Reheating in quintessential inflation via gravitational production of heavy massive particles: a detailed analysis

Abstract

An improved version of the well-known Peebles-Vilenkin model unifying early inflationary era to current cosmic acceleration, is introduced in order to match with the theoretical values of the spectral quantities provided by it with the recent observational data about the early universe.Since the model presents a sudden phase transition, we consider the simplest way to reheat the universe − via the gravitational production of heavy massive particles − which assuming that inflation starts at GUT scales ∼ 10 16 GeV, allows us to use the Wentzel-Kramers-Brillouin (WKB) approximation and consequently this enables us to perform all the calculations in an analytic way.Our results show that the model leads to a maximum temperature at the TeV regime, and passes the bounds to ensure the success of the Big Bang Nucleosynthesis. Finally, we have constrained the quintessence piece of the proposed improved version of the Peebles-Vilenkin model using various astronomical datasets available at present. *

Gravitational production of superheavy dark matter and associated cosmological signatures

“…In this case, dark matter can be produced during inflation and in post-inflationary phases as well. The relevant models of dark matter include Planckian Interacting Dark Matter (PIDM) [3][4][5][6][7], WIMPZILLA [8,9], SUPERWIMP [10], FIMP [11] (the model considered in [3] can be viewed as "FIMPZILLA").…”

The Peebles–Vilenkin quintessential inflation model revisited

“…Then, in order that this overproduction does not alter the BBN success, at the reheating time, the ratio of the energy density of GWs to the energy density of the produced particles has to be less than 10 −2 [16]. As was shown in [41], this bound is satisfied when the reheating occurs via instant preheating, and in the case that the reheating is via gravitational production of superheavy particles, the bound is only satisfied when its decay in lighter particles is after the end of the kination period (see for instance [38]).…”

“…This reheating temperature is compatible with some of the usual Big Bang Nucleosynthesis (BBN) bounds, but it cannot prevent the overproduction of the Gravitational Waves (GWs). To overpass this problem one can consider other kind of reheating mechanisms such as the instant preheating [36,37] or the gravitational production of heavy massive particles [38,39]. Effectively, due to the phase transition from inflation to kination, there is an overproduction of GWs (see for instance Section 5 of [40]).…”

“…where we have used that at reheating time, the energy density and the temperature are related via ρ rh = π 2 30 g rh T 4 rh , where the number of degrees of freedom is, g rh = 107 [53]. We consider reheating via gravitational particle production of massive particles obtaining a reheating temperature is of the order T rh = 100 TeV [38] and via instant preheating leading to a reheating temperature of the order T rh = 10 9 GeV [36,37].…”

“…In this way the observational values of H 0 and Ω m,0 could be obtained directly from the own V α potential, however, the parameter M is completely degenerate as reported from the latest astronomical datasets [38], where the addition of baryon acoustic oscillations data into the cosmic microwave background radiation cannot break such a degeneracy. The low redshifts sample like Pantheon from the Supernovae Type Ia, and the Hubble parameter measurements from the cosmic chronometers also return similar conclusion.…”