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The quantum cosmology of the flat Friedmann-Lema{\^i}tre-Robertson-Walker Universe, filled with a scalar field, is considered in the de Broglie-Bohm (dBB) interpretation framework. A stiff-matter quantum bounce solution is obtained. The…

General Relativity and Quantum Cosmology · Physics 2023-07-24 G. S. Vicente , Rudnei O. Ramos , Vitória N. Magalhães

We propose a novel extension to the recently developed non-commutative Riemannian foliated branch-cut quantum gravity (BCQG). Based on an extended Faddeev-Jackiw symplectic deformation of the conventional Poisson algebra, we investigate…

One presents a phase-space noncommutative extension of Quantum Cosmology in the context of a Kantowski-Sachs (KS) minisuperspace model. We obtain the Wheeler-DeWitt (WDW) equation for the noncommutative system through the ADM formalism and…

High Energy Physics - Theory · Physics 2009-07-24 C. Bastos , O. Bertolami , N. Dias , J. Prata

Bouncing models are alternatives to inflationary cosmology that replace the initial Big-Bang singularity by a `bouncing' phase. A deeper understanding of the initial conditions of the universe, in these scenarios, requires knowledge of…

General Relativity and Quantum Cosmology · Physics 2021-05-27 Karthik Rajeev , Vikramaditya Mondal , Sumanta Chakraborty

This paper discusses the problem of inflation in the context of Friedmann-Robertson-Walker Cosmology. We show how, after a simple change of variables, one can quantize the problem in a way which parallels the classical discussion. The…

High Energy Physics - Theory · Physics 2007-05-23 Marvin Weinstein , Ratin Akhoury

We show that modelling the universe as a pre-geometric system with emergent quantum modes, and then constructing the classical limit, we obtain a new account of space and gravity that goes beyond Newtonian gravity even in the…

General Physics · Physics 2007-09-20 Reginald T Cahill

In this paper we propose a novel unified cosmological model that connects a pre-inflationary epoch, starting at the Planckian time, with the onset of inflation within a single scalar-field framework. The pre-inflationary phase is…

General Relativity and Quantum Cosmology · Physics 2026-05-20 M. Montes , José Edgar Madriz Aguilar , A. Bernal , Diego Allan Reyna

We show that a contracting universe which bounces due to quantum cosmological effects and connects to the hot big-bang expansion phase, can produce an almost scale invariant spectrum of perturbations provided the perturbations are produced…

High Energy Physics - Theory · Physics 2008-11-26 Patrick Peter , E. J. C. Pinho , Nelson Pinto-Neto

A quantum field theory warm inflation model is presented that solves the horizon/flatness problems. The model obtains, from the elementary dynamics of particle physics, cosmological scale factor trajectories that begin in a radiation…

High Energy Physics - Phenomenology · Physics 2008-11-26 Arjun Berera , Marcelo Gleiser , Rudnei O. Ramos

We study noncommutative classical Friedmann-Robertson-Walker cosmological models. The constant curvature of the spatial sections can be positive ($k=1$), negative ($k=-1$) or zero ($k=0$). The matter is represented by a perfect fluid with…

General Relativity and Quantum Cosmology · Physics 2017-01-06 G. Oliveira-Neto , A. R. Vaz

Closed, singularity-free, inflationary cosmological models have recently been studied in the context of general relativity. Despite their appeal, these so called emergent models suffer from a number of limitations. These include the fact…

Astrophysics · Physics 2009-11-10 David J. Mulryne , Reza Tavakol , James E. Lidsey , George F. R. Ellis

To understand mechanisms leading to inflation and late acceleration of the Universe it is important to see how one or a set of quantum fields may evolve such that the classical energy-momentum tensor behave similar to a cosmological…

General Relativity and Quantum Cosmology · Physics 2018-07-17 Houri Ziaeepour

We propose a model of cosmological evolution of the early and late Universe which is consistent with observational data and naturally explains the origin of inflation and dark energy. We show that the de Sitter accelerated expansion of the…

General Physics · Physics 2015-06-03 Leonid Marochnik , Daniel Usikov

It is well known that classical Unimodular Gravity (UG) is equivalent to General Relativity, but is not clear the equivalence at the quantum level. Here we exhibit, in the UG framework, the Quantum Cosmology (QC) for a…

General Relativity and Quantum Cosmology · Physics 2022-08-31 J. A. Astorga-Moreno , Miguel A. García-Aspeitia , E. A. Mena-Barboza

We consider a time independent Schrodinger type equation derived from the equations of motion that drives a single scalar field in a standard cosmology model for inflation in a flat space-time with a Friedman-Robertson-Walker (FRW) metric…

General Relativity and Quantum Cosmology · Physics 2010-01-05 N. Barbosa-Cendejas , M. A. Reyes

Inflation is a necessary cosmic mechanism to cure basic inconsistencies of the standard model of cosmology. These problems are usually `fixed' by postulating the existence of a scalar field (called the ``inflaton''). However, other less ad…

General Relativity and Quantum Cosmology · Physics 2026-01-16 Joan Solà Peracaula , Àlex González-Fuentes , Cristian Moreno-Pulido

We describe the universe as a local, inhomogeneous spherical bubble embedded in a flat matter dominated FLRW universe. Generalized exact Friedmann equations describe the expansion of the universe and an early universe inflationary de Sitter…

Astrophysics · Physics 2007-05-23 J. W. Moffat

In the present paper we have developed a Non-Commutative (NC) generalization of perfect fluid model from first principles, in a Hamiltonian framework. The noncommutativity is introduced at the Lagrangian (particle) coordinate space brackets…

High Energy Physics - Theory · Physics 2017-01-20 Praloy Das , Subir Ghosh

An alternative inflationary model is proposed predicated upon a consideration of the form of the uncertainty principle in a curved background spacetime. An argument is presented suggesting a possible curvature dependence in the correct…

General Relativity and Quantum Cosmology · Physics 2014-05-12 Paul J. Camp , John L. Safko

Noncommutative geometry can provide effective description of physics at very short distances taking into account generic effects of quantum gravity. Inflation amplifies tiny quantum fluctuations in the early universe to macroscopic scales…

Cosmology and Nongalactic Astrophysics · Physics 2011-03-18 Tomi S. Koivisto , David F. Mota