English
Related papers

Related papers: Cosmic acceleration from quantum Friedmann equatio…

200 papers

We give a formulation of quantum cosmology with a pressureless dust and arbitrary additional matter fields. The system has the property that its Hamiltonian constraint is linear in the dust momentum. This feature provides a natural time…

General Relativity and Quantum Cosmology · Physics 2015-05-30 Viqar Husain , Tomasz Pawlowski

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…

Space-time quantum contributions to the classical Einstein equations of General Relativity are determined. The theoretical background is provided by the non-perturbative theory of manifestly-covariant quantum gravity and the…

General Relativity and Quantum Cosmology · Physics 2018-07-18 Claudio Cremaschini , Massimo Tessarotto

We apply the causal interpretation of quantum mechanics to homogeneous and isotropic quantum cosmology where the sources of the gravitational field are either dust or radiation perfect fluids. We find non-singular quantum trajectories which…

General Relativity and Quantum Cosmology · Physics 2009-10-30 J. Acacio de Barros , N. Pinto-Neto , M. A. Sagioro-Leal

General relativity and its cosmological solution predicts the existence of tensor modes of perturbations evolving on top of our Friedman-Lema\^itre-Robertson-Walker expanding Universe. Being gauge invariant and not necessarily coupled to…

General Relativity and Quantum Cosmology · Physics 2023-01-20 Amaury Micheli , Patrick Peter

It is shown that the acceleration of the universe can be understood by considering a F(T) gravity models. For these F(T) gravity models, a variant of the accelerating cosmology reconstruction program is developed. Some explicit examples of…

General Relativity and Quantum Cosmology · Physics 2011-09-23 Ratbay Myrzakulov

In this work the wave functions associated to the quantum relativistic universe, which is described by the Wheeler-DeWitt equation, are obtained. Taking into account different kinds of energy density, namely, matter, radiation, vacuum, dark…

General Relativity and Quantum Cosmology · Physics 2021-07-07 H. S. Vieira , V. B. Bezerra , C. R. Muniz , M. S. Cunha

We review some of the well-known features of quantum cosmology, such as the factor ordering problem, the wave function and the density matrix, for a dark energy dominated universe, where analytical solutions can be obtained. For the…

General Relativity and Quantum Cosmology · Physics 2009-09-29 P. F. Gonzalez-Diaz , S. Robles-Perez

We start by presenting a brief summary of fractional quantum mechanics, as means to convey a motivation towards fractional quantum cosmology. Subsequently, such application is made concrete with the assistance of a case study. Specifically,…

General Relativity and Quantum Cosmology · Physics 2021-05-10 S. M. M. Rasouli , S. Jalalzadeh , P. V. Moniz

We discuss predictions for cosmology which result from the scaling solution of functional flow equations for a quantum field theory of gravity. A scaling solution is necessary to render quantum gravity renormalizable. Our scaling solution…

General Relativity and Quantum Cosmology · Physics 2023-01-13 C. Wetterich

The Einstein equations of general relativity reduce, when the spacetime metric is of the Friedmann--Lemaitre--Robertson--Walker type governing an isotropic and homogeneous universe, to the Friedmann equations, which is a set of nonlinear…

General Relativity and Quantum Cosmology · Physics 2024-07-30 Yisong Yang

In this paper we investigate to which extent noncommutativity, a intrinsically quantum property, may influence the Friedmann-Robertson-Walker cosmological dynamics at late times/large scales. To our purpose it will be enough to explore the…

General Relativity and Quantum Cosmology · Physics 2011-08-10 Octavio Obregon , Israel Quiros

Quantum gravity places entirely new challenges on the formulation of a consistent theory as well as on an extraction of potentially observable effects. Quantum corrections due to the gravitational field are commonly expected to be tiny…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Martin Bojowald

We attempt to find new symmetries in the space-time structure, leading to a modified gravitation at large length scales, which provides the foundations of a quantum gravity at very low energies. This search begins by considering a unified…

General Relativity and Quantum Cosmology · Physics 2007-09-13 Claudio Nassif

On the basis of qualitative theory of differential equations it is shown that dynamic system based on the system of Einstein - Klein - Gordon equations with regard to Friedman Universe has a stable center corresponding to zero values of…

General Relativity and Quantum Cosmology · Physics 2016-09-06 Yurii Ignat'ev

We present perfect fluid Friedmann-Robertson-Walker quantum cosmological models in the presence of negative cosmological constant. In this work the Schutz's variational formalism is applied for radiation, dust, cosmic string, and domain…

General Relativity and Quantum Cosmology · Physics 2008-11-26 P. Pedram , M. Mirzaei , S. Jalalzadeh , S. S. Gousheh

Perfect fluid Friedmann-Robertson-Walker quantum cosmological models for an arbitrary barotropic equation of state $p = \alpha\rho$ are constructed using Schutz's variational formalism. In this approach the notion of time can be recovered.…

General Relativity and Quantum Cosmology · Physics 2021-10-20 F. G. Alvarenga , J. C. Fabris , N. A. Lemos , G. A. Monerat

Quantum effects play an essential role in modern cosmology. Perhaps the most striking example comes from large-scale structures, generally assumed to originate from vacuum quantum fluctuations and stretched by an expansion phase. Inflation…

General Relativity and Quantum Cosmology · Physics 2020-10-08 Emmanuel Frion

The solution of the problem of describing the Friedmann observables (the Hubble law, the red shift, etc.) in quantum cosmology is proposed on the basis of the method of gaugeless Hamiltonian reduction in which the gravitational part of the…

General Relativity and Quantum Cosmology · Physics 2009-10-30 A. M. Khvedelidze , V. V. Papoyan , Yu. G. Palii , V. N. Pervushin

An one-parameter regularization freedom of the Hamiltonian constraint for loop quantum gravity is analyzed. The corresponding spatially flat, homogenous and isotropic model includes the two well-known models of loop quantum cosmology as…

General Relativity and Quantum Cosmology · Physics 2021-11-12 Xiangdong Zhang , Gaoping Long , Yongge Ma