Related papers: Warm inflation with back - reaction: a stochastic …
Inflaton couplings during warm inflation result in the production of a thermal bath. Thermal friction and fluctuations can dominate the standard de Sitter analogues, resulting in a modified slow-roll scenario with a new source of density…
Cosmic inflation may exhibit stochastic periods during which quantum fluctuations dominate over the semi-classical evolution. Extracting observables in these regimes is a notoriously difficult program as quantum randomness makes them fully…
We study the dynamics of scalar metric fluctuations in a non-perturbative variational formalism recently introduced, by which the dynamics of an geometrical scalar field $\theta$, describes the quantum geometrical effects on a Weylian-like…
We calculate the back reaction of cosmological perturbations on a general relativistic variable which measures the local expansion rate of the Universe. Specifically, we consider a cosmological model in which matter is described by a single…
Thermal fluctuations provide the main source of large scale density perturbations in warm inflationary models of the early universe. For the first time, general results are obtained for the power spectrum in the case when the friction…
Warm inflation, its different particle physics model implementations and the implications of dissipative particle production for its cosmology are reviewed. First, we briefly present the background dynamics of warm inflation and contrast it…
We present a new, recursive approach to stochastic inflation which is self-consistent and solves multiple problems which plagued a certain number of previous studies, in particular in realistic contexts where the background spacetime is…
The emergence of time in the matter-gravity system is addressed within the context of the inflationary paradigm. A quantum minisuperspace-homogeneous minimally coupled inflaton system is studied with suitable initial conditions leading to…
I study the gauge-invariant fluctuations of the metric during inflation. In the infrared sector the metric fluctuations can be represented by a coarse-grained field. We can write a Schroedinger equation for the coarse-grained metric…
We study a model for reheating that has been much investigated for parametric resonance, having a quartic interaction of the scalar inflaton with another scalar field. Attention is particularly on the quantum excitations of the inflaton…
Warm inflation dynamics is reviewed. Results on dissipative scalar field dynamics relevant to warm inflation are examined and estimates of radiation production are given.
We discuss the spectrum of scalar density perturbations from warm inflation when the friction coefficient $\Gamma$ in the inflaton equation is dependent on the inflaton field. The spectral index of scalar fluctuations depends on a new…
We prove that the stochastic and standard field-theoretical approaches produce exactly the same results for the amount of light massive scalar field fluctuations generated during inflation in the leading order of the slow-roll…
We study stochastic inflation in the presence of a dynamical gravitational constant. We describe the Arnowitt--Deser--Misner formalism for Jordan--Brans--Dicke theory of gravity with an inflaton field. The inflaton and dilaton scalar fields…
We study the behavior of large-scale (cosmological) modes of back-reaction effects during inflation. We find that the group of modes which describes the very large-scale fluctuations of energy density during inflation due to back-reaction…
Warm inflation has normalized two ideas in cosmology, that in the early universe the initial primordial density perturbations generally could be of classical rather than quantum origin and that during inflation, particle production from…
These lectures cover the basics of inflationary models for the early universe, concentrating particularly on the generation of density fluctuations from scalar-field dynamics. The subsequent gravitational dynamics of these fluctuations in…
We consider the back-reaction of cosmological fluctuations on the local expansion rate averaged over a space-like hypersurface of constant value of a clock field. We show that in the infrared limit, the fluctuations lead to a decrease in…
I consider a power-law inflationary model taking into account back-reaction effects. The interesting result is that the spectrum for the scalar field fluctuations does not depends on the expansion rate of the universe $p$ and that it result…
In this paper, we discuss the warm inflation model with both a Langevin equation and a generalized Langevin equation scenario. As a brief picture to illustrate the basic properties of stochastic differential equation in warm inflation, this…