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Related papers: Quantum cosmology with a curvature squared action

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A cosmological model describing the evolution of n Ricci-flat spaces (n>1) in the presence of 1-component perfect-fluid and minimally coupled scalar field is considered. When the pressures in all spaces are proportional to the density, the…

High Energy Physics - Theory · Physics 2009-09-25 V. D. Ivashchuk , V. N. Melnikov

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

We can solve the Wheeler-DeWitt equation of the small universe enough to metric becomes diagonal and take a Gaussian normal coordinate. Our previous works are concerning to this paper. In this paper, we only write how to solve the…

General Relativity and Quantum Cosmology · Physics 2009-04-24 Shintaro Sawayama

The quantum cosmological wavefunction for a quadratic gravity theory derived from the heterotic string effective action is obtained near the inflationary epoch and during the initial Planck era. Neglecting derivatives with respect to the…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Simon Davis

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 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

The quantum contributions to the gravitational action are relatively easy to calculate in the higher derivative sector of the theory. However, the applications to the post-inflationary cosmology and astrophysics require the corrections to…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-04 Julio C. Fabris , Paulo L. C. de Oliveira , Davi C. Rodrigues , Ilya L. Shapiro , A. M. Velasquez-Toribio

We study a quantization via fractional derivative of a nonminimal derivative coupling cosmological theory, namely, the Fab Four John theory. Its Hamiltonian version presents the issue of fractional powers in the momenta. That problem is…

General Relativity and Quantum Cosmology · Physics 2020-05-08 Isaac Torres , Júlio César Fabris , Oliver Fabio Piattella , Antônio Brasil Batista

We illustrate the crucial role played by decoherence (consistency of quantum histories) in extracting consistent quantum probabilities for alternative histories in quantum cosmology. Specifically, within a Wheeler-DeWitt quantization of a…

General Relativity and Quantum Cosmology · Physics 2011-05-26 David A. Craig , Parampreet Singh

In a former paper we proposed a model for the quantization of gravity by working in a bundle $E$ where we realized the Hamilton constraint as the Wheeler-DeWitt equation. However, the corresponding operator only acts in the fibers and not…

General Relativity and Quantum Cosmology · Physics 2018-10-23 Claus Gerhardt

Canonical formulation for an action containing scalar curvature squared term $(R^2)$ in arbitrary dimension has been performed in maximally symmetric space-time. The quantum dynamics does not alter significantly from the same in…

High Energy Physics - Theory · Physics 2015-06-22 Subhra Debnath , Soumendranath Ruz , Abhik Kumar Sanyal

Quantum-mechanical wave equation for a particle with spin 1 is investigated in presence of external magnetic field in spaces with non-Euclidean geometry with constant positive curvature. Separation of the variable is performed; differential…

Mathematical Physics · Physics 2012-11-26 V. V. Kisel , E. M. Ovsiyuk , O. V. Veko , V. M. Red'kov

In this paper, we study the classical limit and unitary evolution of quantum cosmology by applying the Weyl--Wigner--Groenewold--Moyal formalism of deformation quantization to quantum cosmology of a homogeneous and isotropic universe with…

General Relativity and Quantum Cosmology · Physics 2020-11-06 S. Jalalzadeh , M. Rashki , S. Abarghouei Nejad

The renormalization group in effective quantum gravity can be consistently formulated using the Vilkovisky and DeWitt version of effective action and assuming a non-zero cosmological constant. Taking into account that the vacuum counterpart…

High Energy Physics - Theory · Physics 2022-11-08 Breno L. Giacchini , Tibério de Paula Netto , Ilya L. Shapiro

We introduce a Wheeler-De Witt approach to quantum cosmology based on the low-energy string effective action, with an effective dilaton potential included to account for non-perturbative effects and, possibly, higher-order corrections. We…

High Energy Physics - Theory · Physics 2011-04-15 M. Gasperini

We investigate $(n+1)$--dimensional cosmology with varying speed of light. After solving corresponding Wheeler-DeWitt equation, we obtain exact solutions in both classical and quantum levels for ($c $--$\Lambda$)--dominated Universe. We…

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

Quantum cosmology has traditionally been studied at the level of symmetry-reduced minisuperspace models, analyzing the behavior of wave functions. However, in the absence of a complete full setting of quantum gravity and detailed knowledge…

General Relativity and Quantum Cosmology · Physics 2012-09-18 Martin Bojowald

Quantization in the minisuperspace of non minimal scalar-tensor theories leads to a partial differential equation which is non separable. Through a conformal transformation we can recast the Wheeler-DeWitt equation in an integrable form,…

General Relativity and Quantum Cosmology · Physics 2009-10-31 Julio C. Fabris , Nelson Pinto-Neto , A. F. Velasco

A finite and unitary nonlocal formulation of quantum gravity is applied to the cosmological constant problem. The entire functions in momentum space at the graviton-standard model particle loop vertices generate an exponential suppression…

General Relativity and Quantum Cosmology · Physics 2016-02-08 J. W. Moffat

Different proposals for the wave function of the universe are analyzed, with an emphasis on various forms of the tunneling proposal. The issues discussed include the equivalence of the Lorentzian path integral and outgoing-wave proposals,…

General Relativity and Quantum Cosmology · Physics 2010-04-06 Alexander Vilenkin