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A class of $k$-Essence cosmological models, with a power law kinetic term, is quantised in the mini-superspace. It is shown that for a specific configuration, corresponding to a pressureless fluid, a Schr\"odinger-type equation is obtained…

General Relativity and Quantum Cosmology · Physics 2016-12-28 C. R. Almeida , J. C. Fabris , F. Sbisá , Y. Tavakoli

We consider a Bianchi type III axisymmetric geometry in the presence of an electromagnetic field. A first result at the classical level is that the symmetry of the geometry need not be applied on the electromagnetic tensor $F_{\mu\nu}$; the…

General Relativity and Quantum Cosmology · Physics 2018-04-04 A. Karagiorgos , T. Pailas , N. Dimakis , Petros A. Terzis , T. Christodoulakis

In loop quantum cosmology, the Hamiltonian reduces to a finite difference operator. We study the initial singularity and the large volume limit against the ambiguities in the discretisation and the operator ordering within a homogeneous,…

General Relativity and Quantum Cosmology · Physics 2015-03-17 Tomo Tanaka , Fumitoshi Amemiya , Masahiro Shimano , Tomohiro Harada , Takashi Tamaki

In this letter we study the behavior of non-minimally coupled Einstein-Gauss-Bonnet gravity theories with the constant-roll condition. Recalling the results of the striking GW170817 event, we demand that the velocity of the gravitational…

General Relativity and Quantum Cosmology · Physics 2020-11-10 V. K. Oikonomou , F. P. Fronimos

Our main focus is to explore different models in noncommutative spaces in higher dimensions. We provide a procedure to relate a three dimensional q-deformed oscillator algebra to the corresponding algebra satisfied by canonical variables…

High Energy Physics - Theory · Physics 2014-10-14 Sanjib Dey

Quantum--mechanical operators corresponding to canonical momentum and position of a point--like particle, which follow from the quantum field theory in the general Riemannian space-time, satisfy generally to a deformation of the canonical…

General Relativity and Quantum Cosmology · Physics 2007-05-23 E. A. Tagirov

We explore a cosmological model in which dark matter is non-minimally coupled to gravity at the fluid level. While typically subdominant compared to Standard Model forces, such couplings may dominate dark matter dynamics. We show that this…

General Relativity and Quantum Cosmology · Physics 2025-10-14 Samuele Silveravalle , Andrea Lapi , Francesco Benetti , Stefano Liberati

In this article we perform the Wheeler-DeWitt quantization for Bianchi type $I$ anisotropic cosmological model in the presence of a scalar field minimally coupled to the Einstein-Hilbert gravity theory. We also consider the cosmological…

General Relativity and Quantum Cosmology · Physics 2019-08-14 Saumya Ghosh , Sunandan Gangopadhyay , Prasanta K. Panigrahi

Any canonical quantum theory can be understood to arise from the compatibility of the statistical geometry of distinguishable observations with the canonical Poisson structure of Hamiltonian dynamics. This geometric perspective offers a…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Vishnu Jejjala , Djordje Minic , Chia-Hsiung Tze

Flat cosmological models with a cosmological constant on the order of the Einstein-de Sitter critical density are enigmatic in the sense that there does not appear to be any natural explanation for why there should be a cosmological…

Astrophysics · Physics 2007-05-23 George Chapline

We obtain the wave functions associated to the quantum Newtonian universe with a cosmological constant which is described by the Schr\"{o}dinger equation and discuss some aspects of its dynamics for all forms of energy density, namely,…

General Relativity and Quantum Cosmology · Physics 2019-10-08 H. S. Vieira , V. B. Bezerra , C. R. Muniz , M. S. Cunha

We quantize a homogeneous and isotropic universe for two models of modified teleparallel gravity, wherein an arbitrary function of the boundary term, namely $B$, is present in the action and in the other model a scalar field that is…

General Relativity and Quantum Cosmology · Physics 2024-05-07 H. Amiri , K. Atazadeh , H. Hadi

With approaching quantum/noncommutative models for the deep microscopic spacetime in mind, and inspired by our recent picture of the (projective) Hilbert space as the model of physical space behind basic quantum mechanics, we reformulate…

Quantum Physics · Physics 2021-01-13 Chuan Sheng Chew , Otto C. W. Kong , Jason Payne

A new approach to quantum gravity is presented based on a nonlinear quantization scheme for canonical field theories with an implicitly defined Hamiltonian. The constant mean curvature foliation is employed to eliminate the momentum…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Charles H-T Wang

A key challenge for many quantum gravity approaches is to construct states that describe smooth geometries on large scales. Here we define a family of $(2+1)$-dimensional quantum gravity states which arise from curvature excitations…

General Relativity and Quantum Cosmology · Physics 2018-02-27 Bianca Dittrich

The scheme of using the Chern-Simons action to regularize the gravitational Hamiltonian constraint is extended to including the Lorentzian term in the $k=0$ cosmological model. The Euclidean term and the Lorenzian term are thus regularized…

General Relativity and Quantum Cosmology · Physics 2020-10-12 Jinsong Yang , Cong Zhang , Yongge Ma

The old cosmological-constant (CC) problem indicates an inconsistency of the usual formulation of semiclassical gravity. The usual formulation of semiclassical gravity also seems to be inconsistent with the conventional interpretation of…

General Relativity and Quantum Cosmology · Physics 2007-05-23 H. Nikolic

In this work a new non-minimally coupled model is presented, where a generic function $f(R)$ of the scalar curvature factors the usual Einstein-Hilbert action functional, motivated by relevant results obtained from similar models. Its…

General Relativity and Quantum Cosmology · Physics 2016-11-22 R. P. L. Azevedo , J. Páramos

Using a D = 1 supergravity framework I construct a super-Friedmann equation for an isotropic and homogenous universe including dynamical scalar fields. In the context of quantum theory this becomes an equation for a wave-function of the…

General Relativity and Quantum Cosmology · Physics 2019-02-12 J. W. van Holten

The resolution of the problem of cosmological singularity in the framework of gauge theories of gravitation is discussed. Generalized cosmological Friedmann equations for homogeneous isotropic models filled by interacting scalar fields and…

General Relativity and Quantum Cosmology · Physics 2017-08-23 Albert V. Minkevich