相关论文: On gravitational preheating
We discuss a scenario that gravitinos produced non-thermally by an inflaton decay constitute dark matter in the present universe. We find that this scenario is realized for wide ranges of the inflaton mass and the vacuum expectation value.…
We present a mechanism for dark matter (DM) production involving a self-interacting sector that at early times is ultra-relativistic but far-underpopulated relative to thermal equilibrium (such initial conditions often arise, e.g., from…
This paper proposes two levels of preheating for the inflaton that is non-minimally coupled with gravity. The first level, later named by the quadratic regime, corresponds to the matter-dominated era and is responsible for draining the…
We consider gravitational particle production (GPP) of dark matter (DM) under a supergravity framework, where the $\alpha$-attractor inflation model is used. The particle spectrum is computed numerically and the DM number density is…
Dark matter (DM) interacting only gravitationally with the standard model could have been produced in the early universe by Hawking evaporation of primordial black holes (PBH). This mechanism is viable in a large range of DM mass, spanning…
Primordial inflation and Dark Matter (DM) could both belong to the hidden sector. It is therefore plausible that the inflaton, which drives inflation, could couple to the DM either directly or indirectly, thus providing a common origin for…
Prediction of inflationary observables from the temperature fluctuation of Cosmic Microwave Background (CMB) can play a pivotal role in predicting the reheating dynamics in the early universe. In this work, we highlight how the inflationary…
In this letter, we explore the phenomenological impact of inflationary gravitational particle production in the physics of Dark Matter (DM). Large-scale DM fluctuations generated during inflation behave as gravitational particles upon their…
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…
We present a new mechanism for generating the observed dark matter energy density, through resonant production of vector dark matter during inflation. Resonant amplification of the vector dark matter is achieved through Mathieu…
A kinetic mixing between the axion and the inflaton allows for a production of axion dark matter even if the inflationary Hubble scale is smaller than the zero-temperature axion mass. We analyze the axion dynamics in this recently…
The dynamics of cosmic reheating, that is, on how the energy stored in the inflaton is transferred to the standard model (SM) thermal bath, is largely unknown. In this work, we show that the phenomenology of the nonbaryonic dark matter (DM)…
A generic prediction of the Coleman-Weinberg inflation is the existence of a heavy particle sector whose interactions with the inflaton, the lightest state in this sector, generate the inflaton potential at loop level. For typical…
We show that the modulated reheating mechanism can naturally account for dark radiation, whose existence is hinted by recent observations of the cosmic microwave background radiation and the primordial Helium abundance. In this mechanism,…
Within the framework of an explicit dynamical model, in which we calculate the radiatively-corrected, tree-level potential that sets up inflation, we show that the inflaton can be a significant part of dark matter today. We exhibit…
We study production of primordial black holes (PBHs) during an early matter-dominated phase. As a source of perturbations, we consider either the inflaton field with a running spectral index or a spectator field that has a blue spectrum and…
We show that the decay of the inflaton field may be incomplete, while nevertheless successfully reheating the universe and leaving a stable remnant that accounts for the present dark matter abundance. We note, in particular, that since the…
A concise summary of out-of-equilibrium dark matter production during post-inflationary reheating is presented. We show that the dark matter relic abundance is in general sensitive to the thermalization rate of the inflaton decay products,…
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…
We generalize dark matter production to a two-metric framework whereby the physical metric, which couples to the Standard Model (SM), is conformally and/or disformally related to the metric governing the gravitational dynamics. We show that…