相关论文: Gravitational dark matter production from fermioni…
We study whether a first-order phase transition at the end of inflation can generate the observed dark matter abundance through bubble collisions. The transition occurs in a spectator scalar sector with an inflaton-dependent effective…
The curvaton scenario for the generation of the cosmological curvature perturbation on large scales represents an alternative to the standard slow-roll scenario of inflation in which the observed density perturbations are due to…
Conventional scenarios of purely gravitationally produced dark matter with masses below the Hubble parameter at the end of inflation are in tension with Cosmic Microwave Background (CMB) constraints on the isocurvature power spectrum. We…
We consider gravitational wave production due to parametric resonance at the end of inflation, or ``preheating''. This leads to large inhomogeneities which source a stochastic background of gravitational waves at scales inside the comoving…
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…
In this work, we review gravitational-wave generation in a two-scalar-field cosmological model. The framework relies on a two-field scenario in which warm inflation is unified with the dark sector within a single theoretical description. It…
Inflation generates gravitational waves, which may be observable in the low multipoles of the cosmic microwave background (cmb) anisotropy but only if the inflaton field variation is at least of order the Planck scale. Such a large…
We study cosmological gravitational particle production (CGPP) in Higgs inflation, wherein the inflaton is a scalar field with quartic self-coupling $\lambda$ and a nonminimal coupling to gravity $\xi$, and which may, but need not be, the…
We investigate the large curvature perturbations which can lead to the formation of primordial black holes (PBHs) in the context of no-scale supergravity. Our study does not depend on any exotic scenario, such as scalar potentials with…
The inflationary reheating phase begins when accelerated expansion ends. As all Standard Model particles are coupled to gravity, gravitational interactions will lead to particle production. This includes the thermal bath, dark matter and…
The inflationary 1-loop tensor power spectrum from an excited spectator scalar field is calculated. Recent studies on primordial black holes suggest that the inflationary curvature perturbation may be huge on small scales. An enhanced…
We consider an ultra-light scalar field with a mass comparable to (or lighter than) the Hubble parameter of the present universe, and calculate the time evolution of the energy-momentum tensor of the vacuum fluctuations generated during and…
The motion of a pseudo-scalar field $X$ during inflation naturally induces a significant amplification of the gauge fields to which it is coupled. The amplified gauge fields can source characteristic scalar and tensor primordial…
We study cosmological evolution after inflation in models with non-minimal derivative coupling to gravity. The background dynamics is solved and particle production associated with rapidly oscillating Hubble parameter is studied in detail.…
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 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 compute the non-adiabatic production of heavy fermion during inflation due to its coupling with inflaton. The coupling, partly inspired by axion monodromy, comes from the modulation of the fermion mass by the inflaton field. Even though…
We compute the primordial scalar, vector and tensor metric perturbations arising from quantum field inflation. Quantum field inflation takes into account the nonperturbative quantum dynamics of the inflaton consistently coupled to the…
The phenomenon of cosmological gravitational particle production (CGPP) is expected to occur during the period of inflation and the transition into a hot big bang cosmology. Particles may be produced even if they only couple directly to…
Recently, it was proposed that a small true vacuum universe can inflate spontaneously, in principle. Furthermore, there should be matter creation in vacuum inflation due to quantum fluctuations, and the matter created will influence the…