相关论文: Gravitational production of matter and radiation d…
We consider the production of matter and radiation during reheating after inflation, restricting our attention solely to gravitational interactions. Processes considered are the exchange of a graviton, $h_{\mu \nu}$, involved in the…
We consider the direct $s$-channel gravitational production of dark matter during the reheating process. Independent of the identity of the dark matter candidate or its non-gravitational interactions, the gravitational process is always…
We conduct a systematic investigation of freeze-in during reheating while taking care to include both direct and indirect production of dark matter (DM) via gravitational portals and inflaton decay. Direct production of DM can occur via…
In the first stages of inflationary reheating, the temperature of the radiation produced by inflaton decays is typically higher than the commonly defined reheating temperature $T_{RH} \sim (\Gamma_\phi M_P)^{1/2}$ where $\Gamma_\phi$ is the…
The post-inflationary production of supermassive particles can have profound implications for the thermal history of the universe and may leave observable imprints in the gravitational wave (GW) background. In scenarios where the inflaton…
We study the generation of baryon asymmetry as well as dark matter (DM) in an extended reheating period after the end of slow-roll inflation. Within the regime of perturbative reheating, we consider different monomial potential of the…
We examine the impact of charged lepton Yukawa equilibration on leptogenesis during gravitational reheating. During the post-inflationary era, the inflaton field is assumed to oscillate around the minimum of a monomial potential, leading to…
Assuming axions are potential dark matter (DM) candidate that make up all of the DM abundance, we discuss production of axions via (i) standard misalignment mechanism during the period of reheating and (ii) graviton-mediated 2-to-2…
In supersymmetric models of warm inflation, the large temperature of the radiation bath produced by the dissipative motion of the inflaton field may induce a significant thermal abundance of potentially dangerous gravitinos. While previous…
We discuss the gravitational creation of superheavy particles $\chi$ in an inflationary scenario with a quartic potential and a non-minimal coupling between the inflaton $\varphi$ and the Ricci curvature: $\xi \varphi^2 R/2$. We show that…
The purely gravitational dark matter (PGDM) which interacts with the standard model particles only by gravitational interaction has recently been discussed. Due to its feeble interaction, PGDM may be produced mainly by the gravitational…
A reheating phase in the early universe is an essential part of all inflationary models during which not only the Standard Model (SM) quanta are produced but it can also shed light on the production of dark matter. In this work, we explore…
We compute the density of a spin-$\frac32$ particle, the raritron, produced at the end of inflation due to gravitational interactions. We consider a background inflaton condensate as the source of this production, mediated by the exchange…
We show that a minimal scenario, utilizing only the graviton as an intermediate messenger between the inflaton, the dark sector and the Standard Model (SM), is able to generate $simultaneously$ the observed relic density of dark matter…
Dark matter, one of the fundamental components of the universe, has remained mysterious in modern cosmology and particle physics, and hence, this field is of utmost importance at present moment. One of the foundational questions in this…
Reheating is essential for transforming the cold, vacuum dominated Universe at the end of inflation into the hot thermal bath required by the Standard Model. In many well motivated inflationary models, however, the inflaton has no direct…
Since the gravitational interaction is universal, any particle that ever existed, if kinematically accessible, has to be produced through her. We explore the possibility that dark matter is generated purely from gravitational scatterings…
Models of leptogenesis are constrained by the low reheat temperature at the end of reheating associated with the gravitino bound. However a detailed view of reheating, in which the maximum temperature during reheating, $\Tmax$, can be…
We consider an appealing scenario for the production of purely gravitational dark matter in the background of warm inflation, a mechanism that maintains stable thermal bath during inflation. Through systematic investigation of various…
At high temperatures, gravitinos are generated in inelastic scattering processes with particles that are in thermal equilibrium with the hot primordial plasma. We consider the regeneration of gravitinos that starts with completion of…