Related papers: A First-Quantized Formalism for Cosmological Parti…
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…
We investigate the effects of quantum particle production on a classical sudden singularity occurring at fine time in a Friedmann universe. We use an exact solution to describe an initially radiation-dominated universe that evolves into a…
In this work we focus on the gravitationally influenced adiabatic particle creation process, a mechanism that does not need any dark energy or modified gravity models to explain the current accelerating phase of the universe. Introducing…
Particle production by expanding in the future light cone scalar quantum field is studied by assuming that the initial state is associated with the quasiequilibrium statistical operator corresponding to fluid dynamics. We calculate particle…
In massless scalar field cosmology, imposing the universe's physical volume as fundamentally discrete resolves the big bang singularity via a big bounce. We use quantum field theory on curved background to numerically track the number of…
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…
We reconsider and analyze in detail the problem of particle production in the time dependent background of $c=1$ matrix model where the Fermi sea drains away at late time. In addition to the moving mirror method, which has already been…
After brief personal recollections of the author's long-time friendship with Misha Marinov the problem of particle production by classical time- varying scalar field is discussed. In the quasiclassical limit the calculations are done by…
The formalism to treat quantization and evolution of cosmological perturbations of multiple fluids is described. We first construct the Lagrangian for both the gravitational and matter parts, providing the necessary relevant variables and…
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…
In this paper we calculate the massive particle creation as seen by a stationary observer in a $1+1$ dimensional spacetime compact in space. The Bogolubov transformation relating the annihilation and creation operators between two spacelike…
The method is proposed for the phenomenological description of particle creation by external fields (in the presence of gravitational field or without it). It is shown that, despite the appearance of the non-dynamical degrees of freedom,…
We calculate the Bogolubov coefficients for a metric which describes the snapping of a cosmic string. If we insist on a matching condition for all times {\it and} a particle interpretation, we find no particle creation.
Quantum Cosmology and Gravity are formulated here as the primary and secondary quantizations of the energy constraints by analogy with the historical formulation of quantum field theory. New fact is that both the Universe and its matter are…
We investigate the production of dark matter from curvature perturbations produced during inflation or in standard cosmology, for example during first order phase transitions. Perturbations break Weyl flatness of the…
We investigate particle production from coherent oscillation by using the method based on the Bogolyubov transformation. Especially, we study the case when the amplitude of the oscillation and also the coupling constants with the…
We point out that in the context of quantum fields in time dependent classical backgrounds, the number of created particles with a given momentum largely deviates about its mean value. Since the corresponding Fourier modes are nonlocal,…
Gravitational particle production in time variable metric of an expanding universe is efficient only when the Hubble parameter $H$ is not too small in comparison with the particle mass. In standard cosmology, the huge value of the Planck…
The stochastic method based on the influence functional formalism introduced in an earlier paper to treat particle creation in near-uniformly accelerated detectors and collapsing masses is applied here to treat thermal and near-thermal…
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,…