相关论文: Scalar dark matter production from the inflaton

The gravitational interaction is ubiquitous and the effect of gravitational particle production necessarily contributes to the dark matter abundance. A simple candidate of dark matter is a scalar particle, whose only renormalizable…

It is well known that light scalar fields present during inflation are coherently excited. We show that if the field couples to gravity in a non-minimal way, the fluctuations at large scales are suppressed with respect to the small scales…

Nowadays cosmological inflation is the most accepted mechanism to explain the primordial seeds that led to the structure formation observed in the Universe. Current observations are in well agreement to initial adiabatic conditions, which…

Recent cosmological observations indicate the existence of extra light species, i.e., dark radiation. In this paper we show that signatures of the dark radiation are imprinted in the spectrum of inflationary gravitational waves. If the dark…

Previous numerical investigations of gravitational particle production during the coherent oscillation period of inflation displayed unexplained fluctuations in the spectral density of the produced particles. We argue that these features…

We study the gravitational production of super-Hubble-mass dark matter in the very early universe. We first review the simplest scenario where dark matter is produced mainly during slow roll inflation. Then we move on to consider the cases…

Scalar fields in the minimal supersymmetric standard model may have large field values during inflation. Because of approximate global symmetry, it is plausible that the phase directions of them are nearly massless during inflation and…

Dynamics of long-wave isocurvature perturbations during an inflationary stage in multiple (multi-component) inflationary models is calculated analytically for the case where scalar fields producing this stage interact between themselves…

The origin of dark matter in the universe may be scalar particles produced by amplification of quantum fluctuations during a period of dilaton-driven inflation. We show, for the first time, that a single species of particles, depending on…

Diverse cosmological and astrophysical observations strongly hint at the presence of dark matter and dark energy in the Universe. One of the main goals of Cosmology is to explain the nature of these two components. It may well be that both…

We perform a systematic analysis of dark matter production during post-inflationary reheating. Following the period of exponential expansion, the inflaton begins a period of damped oscillations as it decays. These oscillations and the…

Adiabatic (curvature) perturbations are produced during a period of cosmological inflation that is driven by a single scalar field, the inflaton. On particle physics grounds -- though -- it is natural to expect that this scalar field is…

Motivated by their potential role as dark matter, we study the cosmological evolution of light scalar and vector fields non-minimally coupled to gravity. Our focus is on a situation where the dominant contribution to the energy density…

Dark matter modeled as a classical scalar field that interacts only with gravity and with itself by a potential that is close to quartic at large field values and approaches a quadratic form when the field is small would be gravitationally…

In the transition between inflation and reheating, the curvature scalar typically undergoes oscillations which have significant impact on the density of gravitationally produced particles. The commonly used adiabatic vacuum prescription for…

We investigate the gravitational production of a scalar field $\chi$ with a mass exceeding the Hubble scale during inflation $m_\chi \gtrsim H_I$, employing both analytical and numerical approaches. We demonstrate that the steepest descent…

We derive general analytic formulae for the power spectrum and spectral index of the curvature perturbation produced during inflation driven by a multi-component inflaton field, up to the second order in the slow-roll approximation. We do…

We consider dark matter production during the inflaton oscillation epoch. It is conceivable that renormalizable interactions between dark matter and inflaton may be negligible. In this case, the leading role is played by higher dimensional…

We explore a mechanism to produce a light dark photon dark matter through a coupling between the dark photon field and a spectator scalar field which plays no role in the inflationary expansion of the Universe while rolling down its…

We study preheating in plateau inflation in the Palatini formulation of general relativity, in a special case that resembles Higgs inflation. It was previously shown that the oscillating inflaton field returns to the plateau repeatedly in…