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What does it take for real-deterministic c-valued (i.e., classical, commuting) variables to comply with the Heisenberg uncertainty principle? Here, we construct a class of real-deterministic c-valued variables out of the weak values…

Quantum Physics · Physics 2021-06-23 Agung Budiyono , Hermawan K. Dipojono

Cosmological solutions for covariant canonical gauge theories of gravity are presented. The underlying covariant canonical transformation framework invokes a dynamical space-time Hamiltonian consisting of the Einstein-Hilbert term plus a…

General Relativity and Quantum Cosmology · Physics 2019-06-06 David Benisty , David Vasak , Eduardo Guendelman , Jurgen Struckmeier

Modified theories of gravity have recently been studied by several authors as possibly viable alternatives to the cosmological concordance model. Such theories attempt to explain the accelerating expansion of the universe by changing the…

Astrophysics · Physics 2013-05-29 T. Multamaki , I. Vilja

The implications of an Evolutionary Quantum Gravity are addressed in view of formulating a new dark matter candidate. We consider a Schr\"odinger dynamics for the gravitational field associated to a generic cosmological model and then we…

General Relativity and Quantum Cosmology · Physics 2009-11-11 Marco Valerio Battisti , Giovanni Montani

We study the cosmology of the Randall-Sundrum brane-world where the Einstein-Hilbert action is modified by curvature correction terms: a four-dimensional scalar curvature from induced gravity on the brane, and a five-dimensional…

General Relativity and Quantum Cosmology · Physics 2016-11-09 E. Papantonopoulos

General relativity in three spacetime dimensions is used to explore three approaches to the ``problem of time'' in quantum gravity: the internal Schr\"odinger approach with mean extrinsic curvature as a time variable, the Wheeler-DeWitt…

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

We review combinatorial quantum gravity, an approach which combines Einstein's idea of dynamical geometry with Wheeler's "it from bit" hypothesis in a model of dynamical graphs governed by the coarse Ollivier-Ricci curvature. This drives a…

High Energy Physics - Theory · Physics 2023-11-30 Carlo A. Trugenberger

We give an introduction into quantum cosmology with emphasis on its conceptual parts. After a general motivation we review the formalism of canonical quantum gravity on which discussions of quantum cosmology are usually based. We then…

General Relativity and Quantum Cosmology · Physics 2022-09-23 Claus Kiefer , Barbara Sandhoefer

A simple mapping procedure is presented by which classical orbits and path integrals for the motion of a point particle in flat space can be transformed directly into those in curved space with torsion. Our procedure evolved from…

Quantum Physics · Physics 2008-02-03 H. Kleinert

The Affine Coherent State Quantization procedure is applied to the case of a FRLW universe in the presence of a cosmological constant. The quantum corrections alter the dynamics of the system in the semiclassical regime, providing a…

High Energy Physics - Theory · Physics 2014-09-16 Michaël Fanuel , Simone Zonetti

The formalism to treat quantization and evolution of cosmological perturbations of multiple fluids is described. We first construct the Lagrangian for both the gravitational and matter parts, providing the necessary relevant variables and…

General Relativity and Quantum Cosmology · Physics 2016-02-01 Patrick Peter , Nelson Pinto-Neto , Sandro Dias Pinto Vitenti

In loop quantum cosmology, one has to make a choice of SU(2) irreducible representation in which to compute holonomies and regularize the curvature of the connection. The systematic choice made in the literature is to work in the…

General Relativity and Quantum Cosmology · Physics 2017-04-26 Jibril Ben Achour , Suddhasattwa Brahma , Marc Geiller

Quantum gravity is expected to be necessary in order to understand situations where classical general relativity breaks down. In particular in cosmology one has to deal with initial singularities, i.e. the fact that the backward evolution…

General Relativity and Quantum Cosmology · Physics 2016-10-19 Martin Bojowald

Quantum creation of Universes with compact spacelike sections that have curvature $k$ either closed, flat or open, i.e. $k=\pm1,0$ are studied. In the flat and open cases, the superpotential of the Wheeler De Witt equation is significantly…

General Relativity and Quantum Cosmology · Physics 2009-10-31 D. H. Coule , Jerome Martin

A scale--dependent effective action for gravity is introduced and an exact nonperturbative evolution equation is derived which governs its renormalization group flow. It is invariant under general coordinate transformations and satisfies…

High Energy Physics - Theory · Physics 2009-10-30 M. Reuter

The Maxwell extension of the conformal algebra is presented. With the help of gauging the Maxwell-conformal group, a conformally invariant theory of gravity is constructed. In contrast to the conventional conformally invariant actions, our…

High Energy Physics - Theory · Physics 2020-02-21 Salih Kibaroğlu , Oktay Cebecioğlu

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

The paper extends basic Einstein--Hilbert action by adding a newly proposed invariant constructed from a specific contraction between the Einstein tensor and the energy momentum tensor, encoding a non--minimal coupling between the…

General Relativity and Quantum Cosmology · Physics 2023-02-09 Mihai Marciu , Dana Maria Ioan

Following the idea of a field quantization of gravity as realized in group field theory, we construct a minisuperspace model where the wavefunction of canonical quantum cosmology (either Wheeler-DeWitt or loop quantum cosmology) is promoted…

General Relativity and Quantum Cosmology · Physics 2012-05-02 Gianluca Calcagni , Steffen Gielen , Daniele Oriti

Using both the Born-Oppenheimer idea and the de Broglie-Bohm interpretation of wavefunction we represent in a different way the semiclassical quantum gravity from the Wheeler-DeWitt equation in an oscillating regime which can preserve…

General Relativity and Quantum Cosmology · Physics 2014-11-17 Sang Pyo Kim