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We analyse the relationship between classical chaos and particle creation in Robertson-Walker cosmological models with gravity coupled to a scalar field. Within our class of models chaos and particle production are seen to arise in the same…

General Relativity and Quantum Cosmology · Physics 2009-10-31 Fernando C. Lombardo , Mario Castagnino , Luca Bombelli

Using as dynamical variable the square of the radius of the Universe, we solve analytically the Einstein equations in the framework of Robertson-Walker models where a cosmological constant describing phenomenologically the vacuum energy…

General Relativity and Quantum Cosmology · Physics 2009-10-22 R. Brout , Ph. Spindel

We investigate an asymptotically spatially flat Robertson-Walker spacetime from two different perspectives. First, using von Neumann entropy, we evaluate the entanglement generation due to the encoded information in spacetime. Then, we work…

Quantum Physics · Physics 2017-06-21 Mehrnoosh Farahmand , Hosein Mohammadzadeh , Hossein Mehri-Dehnavi

In this paper, we describe physical effects occurring in the regularized Robertson-Walker spacetime which can reveal the presence of the defect. Our analysis is based on two main physical quantities: the compressive forces acting on (human)…

General Relativity and Quantum Cosmology · Physics 2021-08-02 Emmanuele Battista

The study of particle creation phenomena at the expense of the gravitational field is of great research interest. It might solve the cosmological puzzle single-handedly, without the need for either dark energy or the modified theory of…

General Relativity and Quantum Cosmology · Physics 2018-06-26 Abhik Kumar Sanyal , Subhra Debnath

We study the effect of the non-commutativity on the creation of scalar particles from vacuum in the anisotropic universe space-time. We derive the deformed Klein-Gordon equation up to second order in the non-commutativity parameter using…

High Energy Physics - Theory · Physics 2016-09-06 Slimane Zaim

This document is the Ph.D. thesis of Leonard Parker, submitted to Harvard University in 1966. Over the decades, several generations of physicists have been introduced to the concept of particle creation by gravitational fields, a phenomenon…

General Relativity and Quantum Cosmology · Physics 2025-07-09 Leonard E. Parker

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,…

General Relativity and Quantum Cosmology · Physics 2015-06-04 Ralf Schützhold , William G. Unruh

It is known that time-dependent vacuum expectation value of the background field may lead to abundant particle production in the early Universe. In supersymmetric theories bosons and fermions are produced in a correlated manner that depends…

High Energy Physics - Phenomenology · Physics 2015-10-07 Olga Czerwinska , Seishi Enomoto , Zygmunt Lalak

Particle creation during inflation is considered. It could be important for species whose interaction is of gravitational strength or weaker. A complete but economical formalism is given for spin-zero and spin-half particles, and the…

High Energy Physics - Phenomenology · Physics 2016-08-25 David H. Lyth , David Roberts

We examine reheating in the two-field matter bounce cosmology. In this model, the universe evolves from a matter-dominated phase of contraction to an Ekpyrotic phase of contraction before the nonsingular bounce. The Ekpyrotic phase frees…

General Relativity and Quantum Cosmology · Physics 2014-09-10 Jerome Quintin , Yi-Fu Cai , Robert H. Brandenberger

Kinetic equations for ultrarelativistic particles with due account of gravitational interactions with massive particles in the Robertson-Walker universe are obtained. On the basis of an exact solution of the kinetic equations thus obtained,…

General Relativity and Quantum Cosmology · Physics 2020-07-21 Yu. G. Ignat'ev , A. A. Popov

The features of vacuum particle creation in an external classical field are studied for simplest external field models in $3 + 1$ dimensional QED. The investigation is based on a kinetic equation that is a nonperturbative consequence of the…

High Energy Physics - Phenomenology · Physics 2017-04-05 S. A. Smolyansky , A. D. Panferov , D. B. Blaschke , L. Juchnowski , B. Kaempfer , A. Otto

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

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…

General Relativity and Quantum Cosmology · Physics 2025-10-16 Mustafa Saeed , Irfan Javed , Aiman Nauman

We study the production of charged scalar particles with well defined angular momentum, in the presence of an external Coulomb field on de Sitter expanding universe. This process of particle production is studied as a perturbative…

High Energy Physics - Theory · Physics 2019-03-07 Mihaela-Andreea Baloi

We study point particles in 2+1 dimensional first order gravity using a triangulation to fix the connection and frame-field. The Hamiltonian is reduced to a boundary term which yields the total mass. The triangulation is dynamical with…

General Relativity and Quantum Cosmology · Physics 2017-08-23 Jonathan Ziprick

We consider a model of an elementary particle as a 2 + 1 dimensional brane evolving in a 3 + 1 dimensional space. Introducing gauge fields that live in the brane as well as normal surface tension can lead to a stable "elementary particle"…

General Relativity and Quantum Cosmology · Physics 2008-11-26 E. I. Guendelman , Jacov Portnoy

The scalar particle production from vacuum in the presence of electric field, on the de Sitter spacetime is studied. We use perturbation methods to define the transition amplitude. We obtain that the momentum is not conserved in this…

High Energy Physics - Theory · Physics 2014-08-29 Băloi Mihaela-Andreea

The possibilities of unlike particle correlations for a study of the space-time asymmetries in particle production, including the sequence of particle emission, are demonstrated.

Nuclear Theory · Physics 2007-05-23 R. Lednicky