相关论文: Cosmological Particle Creation Beyond de Sitter

Particle production processes in the expanding universe are described within a simple kinetic model. The equilibrium conditions for a Maxwell-Boltzmann gas with variable particle number are investigated. We find that radiation and…

One of the most striking examples for the production of particles out of the quantum vacuum due to external conditions is cosmological particle creation, which is caused by the expansion or contraction of the Universe. Already in 1939,…

It is proposed that the vacuum admits two different phases as described by the Chaplygin equation of state or its generalised version: a phase where the energy density behaves as if dominated by non-relativistic matter and a de Sitter…

We explore non-adiabatic particle production in a de Sitter universe for a scalar spectator field, by allowing the effective mass $m^2(t)$ of this field and the cosmic time interval between non-adiabatic events to vary stochastically. Two…

Quantum fields in cosmological spacetimes can experience particle production due to their interaction with the expanding background. This effect is particularly relevant for models of the very early Universe, when the energy density…

In this paper, we investigate cosmological particle production using quantum field theory (QFT). We will consider how production of scalar particles can occur in an expanding universe. By introducing a time-dependent energy parameter…

A new cosmological model based on the de Sitter gravity is investigated by dynamical analysis and numerical discussions. Via some transformations, the evolution equations of this model can form an autonomous system with 8 physical critical…

We present a simple and self-consistent cosmology with a phenomenological model of quantum creation of radiation and matter due to decay of the cosmological constant $\Lambda$. The decay drives a non-isentropic inflationary epoch, which…

We study gravitational radiation produced by time changing matter source in de Sitter spacetime. We consider a cosmological Killing horizon instead of the conformal boundary used in the radiation theory in the Minkowski spacetime. The…

In this paper we calculate the particle creation as seen by a stationary observer in 3+1 de Sitter space. This particle creation is calculated using an observer dependent geometrically based definition of time which is used to quantize a…

The production of ultra high-energy cosmic rays in de Sitter invariant vacuum states is considered. Assuming the present-day universe is asymptoting toward a future de Sitter phase, we argue the observed flux of cosmic rays places a bound…

The homogeneous and isotropic radiation dominated universe, following the inflationary stage, is expressed as a spherically symmetric and inhomogeneous spacetime upon a power law type conformal transformation of the null (cosmological)…

We study the phenomenon of mass loss by a scalar charge -- a point particle that acts a source for a noninteracting scalar field -- in an expanding universe. The charge is placed on comoving world lines of two cosmological spacetimes: a de…

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…

A nonsingular deflationary cosmology driven by adiabatic matter creation is proposed. In this scenario there is no preinflationary stage as happens in conventional inflationary models. Deflation starts from a de Sitter spacetime…

The creation of 4d de Sitter (inflationary) boundary gluing two d5 de Sitter bulks on the classical as well as on quantum level (with account of brane QFT via corresponding trace anomaly induced effective action) is discussed. Quantum…

Results on particle creation from vacuum by the gravitational field of the expanding Friedmann Universe are presented. Finite results for the density of particles and the energy density for created particles are given for different exact…

The stability of the de Sitter era of cosmic expansion in spatially curved homogeneous isotropic universes is studied. The source of the gravitational field is an imperfect fluid such that the parameters that characterize it may change with…

Using the dS/QFT correspondence in the context of inflation allows for the study of interesting, otherwise inaccessible physics. In particular, by studying inflation via its dual field theory at the boundary of the de Sitter space, it may…

We present several features of a cosmological model based on the Brans-Dicke-Jordan-Thirry action which is scale invariant with a quartic potential for the Jordan scalar field. We show that the radiation dominated era starts with a closed…