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We propose a Hamiltonian formalism for a generalized Friedmann-Roberson-Walker cosmology model in the presence of both a variable equation of state (EOS) parameter $w(a)$ and a variable cosmological constant $\Lambda(a)$, where $a$ is the…

High Energy Physics - Theory · Physics 2008-11-26 Jie Ren , Xin-He Meng , Liu Zhao

We offer a new proposal for cosmic singularity resolution based upon a quantum cosmology with a unitary bounce. This proposal is illustrated via a novel quantization of a mini-superspace model in which there can be superpositions of the…

General Relativity and Quantum Cosmology · Physics 2018-12-17 Sean Gryb , Karim P. Y. Thébault

In this work, first, we study a flat Friedmann-Robertson-Walker Universe with two scalar fields but only one potential term, which can be thought as a simple quintessence plus a K-essence model. Employing the Hamiltonian formalism we are…

General Relativity and Quantum Cosmology · Physics 2021-07-07 J. Socorro , S. Pérez-Payán , Rafael Hernández , Abraham Espinoza-García , Luis Rey Díaz-Barrón

In this paper we study the cosmological constant emerging from the Wheeler-DeWitt equation as an eigenvalue of the related Sturm-Liouville problem. We employ Gaussian trial functionals and we perform a mode decomposition to extract the…

General Relativity and Quantum Cosmology · Physics 2011-03-22 Remo Garattini , Piero Nicolini

We study a model of quantum cosmology originating from a classical model of gravitation where a self interacting scalar field is coupled to gravity with the metric undergoing a signature transition. We show that there are dual classical…

General Relativity and Quantum Cosmology · Physics 2009-10-31 Farhad Darabi

The Wheeler-DeWitt equation is solved for some scalar-tensor theories of gravitation in the case of homogeneous and isotropic cosmological models.We present general solutions corresponding to cosmological term: (i)\lambda(\phi)=0$ and $(ii)…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Luis O. Pimentel , César Mora

It is well-known that the standard WKB approximation fails to provide semiclassical solutions in the vicinity of turning points. However, turning points arise in many cosmological scenarios. In a previous work, we obtained a new class of…

General Relativity and Quantum Cosmology · Physics 2016-02-12 Antonin Coutant

We study the classical and quantum cosmology of a universe in which the matter source is a massive Dirac spinor field and consider cases where such fields are either free or self-interacting. We focus attention on the spatially flat…

General Relativity and Quantum Cosmology · Physics 2009-11-11 B. Vakili , S. Jalalzadeh , H. R. Sepangi

We study the implications of a noncommutative geometry of the minisuperspace variables for the FRW universe with a conformally coupled scalar field. The investigation is carried out by means of a comparative study of the universe evolution…

High Energy Physics - Theory · Physics 2009-11-10 G. D. Barbosa

We comment on two issues in quantum cosmology, in the context of the Wheeler-De Witt equation and wave function of the Universe: (i) arrow of time and interpretation of the wave function in the classically allowed regions; (ii) stability of…

General Relativity and Quantum Cosmology · Physics 2007-05-23 V. A. Rubakov

In the background of homogeneous and isotropic flat FLRW space-time, both classical and quantum cosmology has been studied for teleparallel dark energy (DE) model. Using Noether symmetry analysis, not only the symmetry vector but also the…

General Relativity and Quantum Cosmology · Physics 2024-07-12 Dipankar Laya , Roshni Bhaumik , Sourav Dutta , Subenoy Chakraborty

The paper addresses the quantization of minisuperspace cosmological models by studying a possible solution to the problem of time and time asymmetries in quantum cosmology. Since General Relativity does not have a privileged time variable…

General Relativity and Quantum Cosmology · Physics 2009-11-07 Mario Castagnino , Gabriel Catren , Rafael Ferraro

We consider a solution to the problem of time in quantum gravity by deparameterisation of the ADM action in terms of York time, a parameter proportional to the extrinsic curvature of a spatial hypersurface. We study a minisuperspace model…

General Relativity and Quantum Cosmology · Physics 2014-12-16 Philipp Roser , Antony Valentini

We explore a possible link between the structure of space at short length scales and the emergence of classical phenomena at macroscopic scales. To this end we adopt the paradigm of non-commutative space at short length scales and…

Quantum Physics · Physics 2022-08-15 IB Pittaway , FG Scholtz

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

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

In the present work, we study the noncommutative version of a quantum cosmology model. The model has a Friedmann-Robertson-Walker geometry, the matter content is a radiative perfect fluid and the spatial sections have zero constant…

General Relativity and Quantum Cosmology · Physics 2016-05-05 G. Oliveira-Neto , M. Silva de Oliveira , G. A. Monerat , E. V. Corrêa Silva

The problem of the physical nature and the cosmological constant genesis is discussed. This problem can't be solved in terms of the current quantum field theory which operates with Higgs and nonperturbative vacuum condensates and takes into…

Astrophysics · Physics 2007-05-23 Vladimir Burdyuzha , Olga Lalakulich , Yuri Ponomarev , Grigory Vereshkov

We apply the formalism of quantum cosmology to models containing a phantom field. Three models are discussed explicitly: a toy model, a model with an exponential phantom potential, and a model with phantom field accompanied by a negative…

High Energy Physics - Theory · Physics 2009-11-11 Mariusz P. Dabrowski , Claus Kiefer , Barbara Sandhoefer

This work applies the principles of quantum cosmology to examine models incorporating a quintom field. Specifically, three distinct models are analyzed: a simplified toy model, a model featuring an exponential quintom potential, and one…

General Relativity and Quantum Cosmology · Physics 2025-07-22 Behzad Tajahmad

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