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We consider the gravity interacting with matter scalar fields and quantized in the minisuperspace approach in which the wave functional is described by the Wheeler-DeWitt equations (WdW). Assuming the domination of the homogeneous and…

High Energy Physics - Theory · Physics 2016-04-08 Alexander A. Andrianov , Oleg O. Novikov , Chen Lan

Bouncing models are alternatives to inflationary cosmology that replace the initial Big-Bang singularity by a `bouncing' phase. A deeper understanding of the initial conditions of the universe, in these scenarios, requires knowledge of…

General Relativity and Quantum Cosmology · Physics 2021-05-27 Karthik Rajeev , Vikramaditya Mondal , Sumanta Chakraborty

We consider two-dimensional quantum gravity endowed with a positive cosmological constant and coupled to a conformal field theory of large and positive central charge. We study cosmological properties at the classical and quantum level. We…

High Energy Physics - Theory · Physics 2025-03-05 Dionysios Anninos , Chiara Baracco , Beatrix Mühlmann

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

In the isotropic quantum cosmological perfect fluid model, the initial singularity can be avoided, while the classical behaviour is recovered asymptotically. We verify if initial anisotropies can also be suppressed in a quantum version of a…

General Relativity and Quantum Cosmology · Physics 2007-05-23 F. G. Alvarenga , A. B. Batista , J. C. Fabris , S. V. B. Goncalves

We study the quantum cosmology of a quadratic $f(R)$ theory with a FRW metric, via one of its equivalent Horndeski type actions, where the dynamics of the scalar field is induced. The classical equations of motion and the Weeler-deWitt…

General Relativity and Quantum Cosmology · Physics 2017-06-22 V. Vázquez-Báez , C. Ramírez

We present a theoretical analysis of the WDW approach to quantum cosmology extended to gravity theories with torsion. The dynamics of the FLRW universe is formulated as a classical Hamiltonian problem of point particle mechanics. Unlike in…

General Relativity and Quantum Cosmology · Physics 2026-04-17 David Vasak , Johannes Kirsch , Juergen Struckmeier

We investigate the classical and quantum dynamics of $f(R)$ gravity's rainbow in the presence of a perfect fluid, employing Schutz's formalism to establish a well-defined notion of time. In the classical regime, we derive and solve the…

General Relativity and Quantum Cosmology · Physics 2025-07-02 Andrés Burton-Villalobos , Giovanni Otalora , Manuel Gonzalez-Espinoza , Yoelsy Leyva

We consider quantum geometrodynamics and parametrized quantum field theories in the framework of the Bohm-de Broglie interpretation. In the first case, and following the lines of our previous work [1], where a hamiltonian formalism for the…

General Relativity and Quantum Cosmology · Physics 2013-06-21 N. Pinto-Neto , E. Sergio Santini

In this work, a flat Friedmann-Robertson-Walker (FRW) universe with dust and a cosmological constant is quantized. By means of a canonical transformation, the classical Hamiltonian is reduced to that of either a harmonic oscillator or…

General Relativity and Quantum Cosmology · Physics 2010-05-12 Edésio M. Barboza , Nivaldo A. Lemos

We give a general method to find exact cosmological solutions for scalar-field dark energy in the presence of perfect fluids. We use the existence of invariant transformations for the Wheeler De Witt (WdW) equation. We show that the…

General Relativity and Quantum Cosmology · Physics 2015-10-02 Andronikos Paliathanasis , Michael Tsamparlis , Spyros Basilakos , John D. Barrow

Any quantum system interacting with a complex environment undergoes decoherence. Empty space is filled with vacuum energy due to matter fields in their ground state and represents an underlying environment that any quantum particle has to…

General Relativity and Quantum Cosmology · Physics 2009-08-26 Paolo M. Bonifacio

We present a Friedmann-Robertson-Walker quantum cosmological model in the presence of Chaplygin gas and perfect fluid for early and late time epoches. In this work, we consider perfect fluid as an effective potential and apply Schutz's…

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

We study the quantum avoidance of the big rip singularity in the Eddington-inspired-Born-Infeld (EiBI) phantom model. Instead of considering a simple phantom dark energy component, which is described by a perfect fluid, we consider a more…

General Relativity and Quantum Cosmology · Physics 2018-11-14 Imanol Albarran , Mariam Bouhmadi-López , Che-Yu Chen , Pisin Chen

I investigate spacetime singularities from the point of view of the wavefunction of the universe. In order to extend the classical notion of geodesic incompleteness one has to include the proper time of an observer as a degree of freedom in…

General Relativity and Quantum Cosmology · Physics 2025-11-14 Federico Piazza

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

One of the main interest in quantum cosmology is to determine boundary conditions for the wave function of the universe which can predict observational data of our universe. For this purpose, we solve the Wheeler-DeWitt equation for a…

General Relativity and Quantum Cosmology · Physics 2017-01-23 Hiroshi Suenobu , Yasusada Nambu

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 dissertation investigates questions arising in the consistent histories formulation of the quantum mechanics of closed systems. Various criteria for approximate consistency are analysed. The connection between the Dowker-Halliwell…

Quantum Physics · Physics 2007-05-23 Jim McElwaine

Inspired by Mott's (1929) analysis of particle tracks in a cloud chamber, we consider a simple model for quantum cosmology which includes, in the total Hamiltonian, model detectors registering whether or not the system, at any stage in its…

General Relativity and Quantum Cosmology · Physics 2009-10-31 J. J. Halliwell
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