English
Related papers

Related papers: Particle creation in a Robertson-Walker Universe r…

200 papers

We study the entanglement between two modes of Dirac field in an expanding spacetime characterized by the Robertson-Walker metric. This spacetime model turns out to be asymptotically (in the remote past and far future regions) Minkowskian.…

General Relativity and Quantum Cosmology · Physics 2014-01-21 Shahpoor Moradi , Roberto Pierini , Stefano Mancini

In this work we solve Dirac equation by using the method of seperation of variables. Then we analyzed the particle creation process. To compute the density number of particles created Bogoliubov transformation technique is used.

General Relativity and Quantum Cosmology · Physics 2009-11-07 Ali Havare , Taylan Yetkin , Murat Korunur

The problem of particle creation in cosmology concerning whether the results for the number of particles are infinite or finite is discussed for scalar and spinor particles in Friedmann expanding Universe. It is shown that the results are…

General Relativity and Quantum Cosmology · Physics 2020-04-08 A. A. Grib , Yu. V. Pavlov

We show that global de Sitter space is unstable to particle creation, even for a massive free field theory with no self-interactions. The O(4,1) de Sitter invariant state is a definite phase coherent superposition of particle and…

General Relativity and Quantum Cosmology · Physics 2014-05-28 Paul R. Anderson , Emil Mottola

Cosmological gravitational particle production (GPP) is a generic mechanism by which particles are produced during the inflationary epoch. In this work we consider the GPP of massive scalars in an effort to fully understand the spectrum of…

High Energy Physics - Phenomenology · Physics 2025-01-13 Leah Jenks , Edward W. Kolb , Keyer Thyme

We construct stationary flat three-dimensional Lorentzian manifolds with singularities that are obtained from Euclidean surfaces with cone singularities and closed one-forms on these surfaces. In the application to (2+1)-gravity, these…

Differential Geometry · Mathematics 2014-03-20 Thierry Barbot , Catherine Meusburger

There is an exact correspondence between the simplest solution to Einstein's equations describing the formation of a black hole and a particular moving mirror trajectory. In both cases the Bogolubov coefficients in 1+1 dimensions are…

General Relativity and Quantum Cosmology · Physics 2018-07-27 Michael R. R. Good , Paul R. Anderson , Charles R. Evans

We consider the question of properly defining energy and momenta for non asymptotic Minkowskian spaces in general relativity. Only spaces of this type, whose energy, linear 3-momentum, and intrinsic angular momentum vanish, would be…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Joan Josep Ferrando , Ramon Lapiedra , Juan Antonio Morales

It is well established that at early times, long before the time of radiation-matter equality, the universe could have been well described by a spatially flat, radiation only model. In this letter we consider the whole primeval universe as…

General Relativity and Quantum Cosmology · Physics 2015-02-17 Julian Gonzalez-Ayala , F. Angulo-Brown

We propose that the Universe was created from "Nothing" with a relatively small particles number and it very quick relaxed to quasiequilibrium state at the Planck parameters. The classic cosmological solution for this Universe, with the…

Astrophysics · Physics 2009-10-28 V. Burdyuzha , Yu. Ponomarev , O. Lalaculich , G. Vereshkov

Cosmological gravitational particle production (CGPP) is the creation of particles in an expanding universe due solely to their gravitational interaction. These particles can play an important role in the cosmic history through their…

Cosmology and Nongalactic Astrophysics · Physics 2025-01-29 Edward W. Kolb , Andrew J. Long

I describe the logical basis of the method that I developed in 1962 and 1963 to define a quantum operator corresponding to the observable particle number of a quantized free scalar field in a spatially-flat isotropically expanding (and/or…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-05 Leonard Parker

An exact solution is obtained for a massive scalar field conformally coupled with the curvature in a cosmological model with the scale factor $a(t) = a_0 / |t|$, corresponding to background matter with the equation of state $ p = - 5…

General Relativity and Quantum Cosmology · Physics 2010-04-21 Yu. V. Pavlov

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…

General Relativity and Quantum Cosmology · Physics 2012-07-06 John D. Barrow , Antonio B. Batista , Julio C. Fabris , M. J. S. Houndjo

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…

High Energy Physics - Phenomenology · Physics 2021-06-23 S. V. Akkelin

In inflationary cosmology, the rapid expansion of the early universe resulted in the spontaneous production of cosmological particles from vacuum fluctuations, observable today in the cosmic microwave background anisotropies. The analogue…

We discuss several aspects of particle production in: (a) time dependent electric field and (b) expanding Friedmann background. In the first part of the paper, we provide an algebraic mapping between the differential equations describing…

General Relativity and Quantum Cosmology · Physics 2019-08-28 Karthik Rajeev , Sumanta Chakraborty , T. Padmanabhan

We study creation and time evolution of particle number asymmetry with nonequilibrium quantum field theory. We introduce a model of a neutral scalar and a complex scalar and it has CP violating and particle number violating features.…

High Energy Physics - Phenomenology · Physics 2019-04-11 Takuya Morozumi , Keiko I. Nagao , Apriadi Salim Adam , Hiroyuki Takata

In the present article we obtain, by separation of variables, an exact solution to the Dirac equation with anomalous momentum for an electrically neutral massless particle in a Bertotti-Robinson universe. We discuss the phenomenom of…

General Relativity and Quantum Cosmology · Physics 2009-10-22 V. M. Villalba

We construct a model for the universe based on the existence of quantum fields at finite temperature in the background of Robertson-Walker spacetime in presence of a non-zero cosmological constant. We discuss the vacuum regime in the light…

General Relativity and Quantum Cosmology · Physics 2011-10-10 M. B. Altaie , U. Al-Ahmad