Related papers: Quantum interference in gravitational particle pro…
We show that a quadratic $U(1)$-breaking term, together with an effective chemical potential induced by a dimension five derivative coupling between the inflaton and the $U(1)$ current, can drive efficient particle production during…
Large amplitude oscillation of cosmic field that may occur right after inflation and in the decay process of weakly interacting fields gives rise to violent particle production via the parametric resonance. In the large amplitude limit the…
Baryogenesis driven by curvature effects is investigated by taking into account gravitationally induced particle production in the very early Universe. In our scenario, the baryon asymmetry is generated dynamically during an inflationary…
We consider trapped inflation in a higher dimensional field space: particle production at a dense distribution of extra species points leads to a terminal velocity at which inflation can be driven in steep potentials. We compute an…
Particle creation during inflation is considered. It could be important for species whose interaction is of gravitational strength or weaker. A complete but economical formalism is given for spin-zero and spin-half particles, and the…
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…
We study a massive inflaton minimally coupled to the FRW Universe using the semiclassical gravity derived from canonical quantum gravity. It is found that the semiclassical quantum gravity leads to the power-law expansion $t^{2/3}$ in an…
The main goal of this paper is to derive the primordial power spectrum for the scalar perturbations generated as a result of quantum fluctuations during an inflationary pe- riod by an alternative approach of field quantization[1-3].…
We identify a characteristic pattern in the scalar-induced stochastic gravitational wave background from particle production during inflation. If particle production is sufficiently efficient, the scalar power spectrum exhibits…
We discuss the effects of cosmic phase transition on the spectrum of primordial gravitational waves generated during inflation. The energy density of the scalar condensation responsible for the phase transition may become sizable at the…
We investigate the gravitational particle production from vacuum for a minimally coupled fermionic spectator field during a single-field inflationary phase. We observe that metric perturbations arising from the quantum fluctuations of a…
The (large-scale) structures we observe in the Universe are classical, but within the inflationary scenario they do originate from quantum fluctuations. This leads to the question: ''How did this quantum-to-classical transition occur?''. A…
Quantum gravitational back-reaction offers the potential of simultaneously resolving the problem of the cosmological constant and providing a natural model of inflation in which scalars play no special role. In this model inflation begins…
The decoherence of quantum fluctuations into classical perturbations during inflation is discussed. A simple quantum mechanical argument, using a spatial particle wavefunction rather than a field description, shows that observable…
Particle production and its effects on the inflaton field are investigated during the preheating phase of chaotic inflation using a model consisting of a massive scalar inflaton field coupled to N massless quantum scalar fields. The effects…
Interactions between the inflaton and any additional fields can lead to isolated bursts of particle production during inflation (for example from parametric resonance or a phase transition). Inflationary particle production leaves localized…
Understanding the quantum nature of the gravitational field is undoubtedly one of the greatest challenges in theoretical physics. Despite significant progress, a complete and consistent theory remains elusive. However, in the weak field…
A theory of gravitational production of light scalar particles during and after inflation is investigated. We show that in the most interesting cases where long-wavelength fluctuations of light scalar fields can be generated during…
Formulae are derived for the spectra of scalar curvature perturbations and gravitational waves produced during inflation, special cases of which include power law inflation, natural inflation in the small angle approximation and inflation…
The phenomenon of resonant production of particles {\it after} inflation has received much attention in the past few years. In a new application of resonant production of particles, we consider the effect of a resonance {\em during}…