English
Related papers

Related papers: Quantum string cosmology in the phase space

200 papers

We discuss the possibility of quantum transitions from the string perturbative vacuum to cosmological configurations characterized by isotropic contraction and decreasing dilaton. When the dilaton potential preserves the sign of the Hubble…

High Energy Physics - Theory · Physics 2019-08-17 A. Buonanno , M. Gasperini , M. Maggiore , C. Ungarelli

We endorse the context that the cosmological constant problem is a quantum cosmology issue. Therefore, in this paper we investigate the $q$-deformed Wheeler-DeWitt equation of a spatially closed homogeneous and isotropic Universe in the…

General Relativity and Quantum Cosmology · Physics 2023-05-02 S. Jalalzadeh , A. J. S. Capistrano , P. V. Moniz

Several new results regarding the quantum cosmology of the quadratic gravity theory derived from the heterotic string effective action are presented. After describing techniques for solving the Wheeler-De Witt equation with appropriate…

General Relativity and Quantum Cosmology · Physics 2009-10-31 Simon Davis , Hugh Luckock

$f(Q)$ symmetric-teleparallel gravity is considered in view of Quantum Cosmology. Specifically, we derive cosmological equations for $f(Q)$ models and then investigate the related energy conditions. In the minisuperspace formalism, the…

General Relativity and Quantum Cosmology · Physics 2023-07-04 Francesco Bajardi , Salvatore Capozziello

Quantum cosmology may permit to determine the initial conditions of the Universe. In particular, it may select a specific model between many possible classical models. In this work, we study a quantum cosmological model based on the string…

General Relativity and Quantum Cosmology · Physics 2009-11-10 F. G. Alvarenga , A. B. Batista , J. C. Fabris

For a FRW-spacetime coupled to an arbitrary real scalar field, we endow the solution space of the associated Wheeler-DeWitt equation with a Hilbert-space structure, construct the observables, and introduce the physical wave functions of the…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Ali Mostafazadeh

One of the central difficulties in the quantization of the gravitational interactions is that they are described by a set of constraints. The standard strategy for dealing with the problem is the Dirac quantization procedure, which leads to…

General Relativity and Quantum Cosmology · Physics 2022-06-15 Grzegorz Czelusta , Jakub Mielczarek

The paper develop the alternative formulation of quantum mechanics known as the phase space quantum mechanics or deformation quantization. It is shown that the quantization naturally arises as an appropriate deformation of the classical…

Mathematical Physics · Physics 2011-09-27 Maciej Blaszak , Ziemowit Domanski

Bimetric gravity theories describes gravitational interactions in the presence of an extra spin-2 field. The Hassan-Rosen (HR) nonlinear massive minimal bigravity theory is a ghost-free bimetric theory formulated with respect a flat,…

General Relativity and Quantum Cosmology · Physics 2021-05-28 Julio César Vera-Hernández

To quantify the effect of decoherence in quantum measurements, it is desirable to measure not merely the square modulus of the spatial wavefunction, but the entire density matrix, whose phases carry information about momentum and how pure…

Quantum Physics · Physics 2009-10-30 Max Tegmark

Second quantization of a classical nonrelativistic one-particle system as a deformation quantization of the Schrodinger spinless field is considered. Under the assumption that the phase space of the Schrodinger field is $C^{\infty}$, both,…

High Energy Physics - Theory · Physics 2008-11-26 H. Garcia-Compean , J. F. Plebanski , M. Przanowski , F. J. Turrubiates

Wigner's quasi-probability distribution function in phase-space is a special (Weyl) representation of the density matrix. It has been useful in describing quantum transport in quantum optics; nuclear physics; decoherence (eg, quantum…

High Energy Physics - Theory · Physics 2008-11-26 Cosmas K Zachos

The present work deals with quantum cosmology for non-minimally coupled scalar field in the background of FLRW space--time model. The Wheeler-DeWitt equation is constructed and symmetry analysis is carried out. The Lie point symmetries are…

General Relativity and Quantum Cosmology · Physics 2019-06-26 Sourav Dutta , Muthusamy Lakshmanan , Subenoy Chakraborty

A quantum equivalence principle is formulated by means of a gravitational phase operator which is an element of the Poincare group. This is applied to the spinning cosmic string which suggests that it may, but not necessarily, contain…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Jeeva S. Anandan

We review the Weyl-Wigner formulation of quantum mechanics in phase space. We discuss the concept of Narcowich-Wigner spectrum and use it to state necessary and sufficient conditions for a phase space function to be a Wigner distribution.…

High Energy Physics - Theory · Physics 2009-11-11 Nuno Costa Dias , Joao Nuno Prata

We give a definition for the Wigner function for quantum mechanics on the Bohr compactification of the real line and prove a number of simple consequences of this definition. We then discuss how this formalism can be applied to loop quantum…

Mathematical Physics · Physics 2008-11-26 Christopher J. Fewster , Hanno Sahlmann

The quantum cosmology of a higher-derivative derivative gravity theory arising from the heterotic string effective action is reviewed. A new type of Wheeler-DeWitt equation is obtained when the dilaton is coupled to the quadratic curvature…

General Relativity and Quantum Cosmology · Physics 2011-04-15 Simon Davis

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 deformation quantization formalism is applied to the linearized gravitational field. Standard aspects of this formalism are worked out before the ground state Wigner functional is obtained. Finally, the propagator for the graviton is…

High Energy Physics - Theory · Physics 2015-05-30 Hugo Garcia-Compean , Francisco J. Turrubiates

The purpose of this paper is to introduce a new way to inquire the quantum cosmology for a certain gravitational theory. Normally, the quantum cosmological model is introduced as the minisuperspace theory which is obtained by reducing the…

General Relativity and Quantum Cosmology · Physics 2016-06-07 Miao He , Zi-Liang Wang , Jian-Bo Deng , Hua Chen