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Related papers: Particle Creation in some LRS Bianchi I models

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The free Dirac equation is solved in a Bianchi Type I space-time, which represents a homogeneous but anisotropic universe, to show the creation of fermionic particles. It is found that unlike in the isotropic case, massless fermion…

General Relativity and Quantum Cosmology · Physics 2019-05-22 Amit Bhoonah

We investigate the fate of particle production in an expanding universe dominated by a perfect fluid with equation of state $p = \alpha\rho$. The rate of particle production, using the Bogolioubov coefficients, are determined exactly for…

General Relativity and Quantum Cosmology · Physics 2012-07-06 A. B. Batista , J. C. Fabris , M. J. S. Houndjo

We reanalyze the problem of particle creation in a 3+1 spatially closed Robertson-Walker space-time. We compute the total number of particles produced by this non-stationary gravitational background as well as the corresponding total energy…

High Energy Physics - Theory · Physics 2008-11-26 F. Pascoal , C. Farina

We examine the anisotropy originated from a first-order vacuum phase transitions through three-dimensional numerical simulations. We apply Bianchi Type-I metric to our model that has one scalar field minimally coupled to the gravity. We…

General Relativity and Quantum Cosmology · Physics 2023-08-01 A. Savaş Arapoğlu , A. Emrah Yükselci

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…

General Relativity and Quantum Cosmology · Physics 2009-10-28 Winfried Zimdahl , Josep Triginer , Diego Pavon

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…

High Energy Physics - Phenomenology · Physics 2016-11-23 A. D. Dolgov

We have obtained analytical exact solutions of the Dyer-Roeder equation in a cosmological model where creation of particles occurs at the expenses of the gravitational field. We discussed the influences of inhomogeneities in the path of a…

Astrophysics · Physics 2009-11-10 M. de Campos , J. A. Souza

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…

High Energy Physics - Theory · Physics 2015-06-26 D. J. Lamb , A. Z. Capri , M. Kobayashi

In this work we present the cosmological dynamics of interacting dark energy models in the framework of particle creation mechanism. The particle creation mechanism presented here describes the true non equilibrium thermodynamics of the…

General Relativity and Quantum Cosmology · Physics 2017-06-07 Sujay Kr. Biswas , Wompherdeiki Khyllep , Jibitesh Dutta , Subenoy Chakraborty

We investigate how entanglement entropy can drive particle creation, deriving explicit relations between entropy and the radiated particle spectrum, the total number of particles, and the total energy. Particle production is computed for…

Quantum Physics · Physics 2026-02-04 Michael R. R. Good , Evgenii Ievlev , Eric V. Linder

The nature of cosmological solutions for a homogeneous, anisotropic Universe given by a Bianchi type-I (BI) model in the presence of a Cosmological constant $\Lambda$ is investigated by taking into account dissipative process due to…

General Relativity and Quantum Cosmology · Physics 2015-05-01 Bijan Saha , V. Rikhvitsky

In homogeneous and isotropic loop quantum cosmology, gravity can behave repulsively at Planckian energy densities leading to the replacement of the big bang singularity with a big bounce. Yet in any bouncing scenario it is important to…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Dah-Wei Chiou , Kevin Vandersloot

We discuss the dynamical effects of bulk viscosity and particle creation on the early evolution of the Friedmann -Robertson -Walker model in the framework of open thermodynamical systems. We consider bulk viscosity and Particle creation as…

General Relativity and Quantum Cosmology · Physics 2015-03-02 C. P. Singh

We further investigate novel features of the $T-$vacuum state, originally defined in the context of quantum field theory in a (1+1) dimensional radiation dominated universe [Modak, JHEP 12, 031 (2020)]. Here we extend the previous work to a…

General Relativity and Quantum Cosmology · Physics 2025-05-14 Dhamar S. Astilla , Sujoy K. Modak , Enrique Salazar

A model of a cloud formed by massive strings is used as a source of Bianchi type II. We assumed that the expansion $(\theta)$ in the model is proportional to the shear $(\sigma)$. To get exact solution, we have considered the equation of…

General Physics · Physics 2015-06-12 Hassan Amirhashchi

We consider cosmological particle production in 1+1 dimensional string theory. The process is described most efficiently in terms of anomalies, but we also discuss the explicit mode expansions. In matrix cosmology the usual vacuum ambiguity…

High Energy Physics - Theory · Physics 2009-11-10 Sumit R. Das , Joshua L. Davis , Finn Larsen , Partha Mukhopadhyay

This paper explores the phenomenon of particle creation associated with cosmic strings in de Sitter spacetime, a model that represents the universe exponential expansion. We examine how the presence of cosmic strings in a de Sitter…

General Relativity and Quantum Cosmology · Physics 2025-06-10 Bilgehan Baris Oner , Ozlem Yesiltas

We consider a massless scalar field in 1+1 dimensions satisfying a Robin boundary condition (BC) at a non-relativistic moving boundary. We derive a Bogoliubov transformation between input and output bosonic field operators, which allows us…

High Energy Physics - Theory · Physics 2009-11-11 B Mintz , C Farina , P A Maia Neto , R B Rodrigues

In this paper we study the creation of super-massive real scalar particles in the framework of a $f(R)=R-\beta/R^n$ modified gravity theory, with parameters constrained by observational data. The analysis is restrict to a homogeneous and…

General Relativity and Quantum Cosmology · Physics 2017-05-18 S. H. Pereira , R. F. L. Holanda

The theoretical and observational consequences of thermodynamics of open systems, which allow particle creation are investigated in modified $f(R,T)$ ($R$ is the Ricci scalar and $T$ is the trace of energy-momentum tensor) theory of gravity…

General Relativity and Quantum Cosmology · Physics 2014-08-26 C. P. Singh , Vijay Singh