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Related papers: Matter in inhomogeneous loop quantum cosmology: th…

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In present article we consider an axion F(R) gravity model and described with the help of holographic principle the cosmological models of viscous dark fluid coupled with axion matter in a spatially flat Friedmann-Robertson-Walker (FRW)…

General Relativity and Quantum Cosmology · Physics 2021-09-29 A. A. Saharian , A. V. Timoshkin

We investigate the canonical quantization in the framework of N=1 simple supergravity for the case of a very simple gravitational midisuperspace described by Gowdy $T^3$ cosmological models. We consider supersymmetric quantum cosmology in…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Alfredo Macias , Abel Camacho , Jutta Kunz , Claus Laemmerzahl

We develop a general framework for effective equations of expectation values in quantum cosmology and pose for them the quantum Cauchy problem with no-boundary and tunneling wavefunctions. Cosmological configuration space is decomposed into…

General Relativity and Quantum Cosmology · Physics 2009-10-31 A. O. Barvinsky , D. V. Nesterov

The Hawking minisuperspace model (closed FRW geometry with a homogeneous massive scalar field) provides a fairly non-trivial testing ground for fundamental problems in quantum cosmology. We provide evidence that the Wheeler-DeWitt equation…

General Relativity and Quantum Cosmology · Physics 2009-10-28 Franz Embacher

The spatially flat and isotropic cosmological model of Brans-Dicke theory with coupling parameter $\omega\neq-3/2$ is quantized by the approach of loop quantum cosmology. An interesting feature of this model is that, although the…

General Relativity and Quantum Cosmology · Physics 2013-04-16 Xiangdong Zhang , Michal Artymowski , Yongge Ma

We consider the k=1 Friedman-Robertson-Walker (FRW) model within loop quantum cosmology, paying special attention to the existence of an ambiguity in the quantization process. In spatially non-flat anisotropic models such as Bianchi II and…

General Relativity and Quantum Cosmology · Physics 2011-08-12 Alejandro Corichi , Asieh Karami

Loop quantum gravity methods are applied to a symmetry-reduced model with homogeneity in two dimensions, derived from a Gowdy model [5,6]. The conditions for propagation of unidirectional plane gravitational waves at exactly the speed of…

General Relativity and Quantum Cosmology · Physics 2025-04-28 F. Hinterleitner

We investigate the impact of conformal transformations on the physical properties of solution trajectories in nonmetricity gravity. Specifically, we explore the phase-space and reconstruct the cosmological history of a spatially flat…

General Relativity and Quantum Cosmology · Physics 2023-12-19 Nikolaos Dimakis , Kevin Duffy , Alex Giacomini , Alexander Yu. Kamenshchik , Genly Leon , Andronikos Paliathanasis

We analyze two different algorithms for constructing weakly inhomogeneous models for the low-redshift Universe, in order to provide a tool for testing the geodesic dynamics, within the sphere of validity for the Universe acceleration. We…

General Relativity and Quantum Cosmology · Physics 2020-07-14 P. Marcoccia , G. Montani

In this paper, working in a Friedman-Lemaitre-Robertson-Walker (FLRW), first, in the flat case, we recover the generalized Friedman equation of Quantum Loop cosmology, and therefore the cosmological bounce, in the framework of modified…

General Relativity and Quantum Cosmology · Physics 2021-01-20 Alessandro Casalino , Bruno Sanna , Lorenzo Sebastiani , Sergio Zerbini

Fock space quantization of Hamiltonian constraints of General Relativity and thermodynamics of quantum states for flat Friedmann-Lemaitre-Robertson-Walker metrics is presented.

General Relativity and Quantum Cosmology · Physics 2011-04-11 L. A. Glinka

Loop quantum gravity corrections, in the presence of inhomogeneities, can lead to a deformed constraint algebra. Such a deformation implies that the effective theory is no longer generally covariant. As a consequence, the geometrical…

General Relativity and Quantum Cosmology · Physics 2015-06-17 Rakesh Tibrewala

The problems encountered in trying to quantize the various cosmological models, are brought forward by means of a concrete example. The Automorphism groups are revealed as the key element through which G.C.T.'s can be used for a general…

General Relativity and Quantum Cosmology · Physics 2011-07-19 T. Christodoulakis

The $f(R)$ gravity models formulated in Einstein conformal frame are equivalent to Einstein gravity together with a minimally coupled scalar field. The scalar field couples with the matter sector and the coupling term is given by the…

General Relativity and Quantum Cosmology · Physics 2012-07-24 Yousef Bisabr

We analyze the tomographic representation for the Friedmann-Robertson-Walker (FRW) model within the Loop Quantum Cosmology framework. We focus on the Wigner quasi-probability distributions associated with Gaussian and Schr\"odinger cat…

General Relativity and Quantum Cosmology · Physics 2021-04-21 Jasel Berra-Montiel , Alberto Molgado

We investigate the quantum cosmology of a closed spatially homogeneous and isotropic Friedmann-Lema\^itre-Robertson-Walker (FLRW) minisuperspace model with electromagnetic radiation as matter content. We solve the corresponding…

General Relativity and Quantum Cosmology · Physics 2022-07-15 S. Jalalzadeh

We study the effects of an information-theoretically motivated nonlinear correction to the Wheeler-deWitt equation in the minisuperspace scheme for flat, $k=0$, Friedmann-Robertson-Walker (FRW) universes. When the only matter is a…

General Relativity and Quantum Cosmology · Physics 2014-11-18 Le-Huy Nguyen , Rajesh R. Parwani

The use of techniques from loop quantum gravity for cosmological models may solve some difficult problems in quantum cosmology. The solutions under a number of circumstances have been well studied. We will analyse the behaviour of solutions…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Daniel Green , William G. Unruh

We employ a three fluid model in order to construct a cosmological model in the Friedmann Robertson Walker flat spacetime, which contains three types of matter dark energy, dark matter and a perfect fluid with a linear equation of state.…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-03 Michael Tsamparlis , Andronikos Paliathanasis

In this Letter by utilizing the Noether symmetry approach in cosmology, we attempt to find the tachyon potential via the application of this kind of symmetry to a flat Friedmann-Robertson-Walker (FRW) metric. We reduce the system of…

General Physics · Physics 2011-09-01 Mubasher Jamil , F. M. Mahomed , D. Momeni