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We discuss the deformation quantization approach for the teaching of quantum mechanics. This approach has certain conceptual advantages which make its consideration worthwhile. In particular, it sheds new light on the relation between…

Quantum Physics · Physics 2015-06-26 Allen C. Hirshfeld , Peter Henselder

A review is given of recent work on topology changing solutions to the first order form of general relativity. These solutions have metrics which are smooth everywhere, invertible almost everywhere, and have bounded curvature. The…

High Energy Physics - Theory · Physics 2007-05-23 Gary T. Horowitz

Instead of assuming that they depend only on the background variables, we investigate the hypothesis that counter-terms appearing in the deformed algebra approach to loop quantum cosmology depend on the full phase-space variables. We derive…

General Relativity and Quantum Cosmology · Physics 2025-10-28 Maxime De Sousa , Aurélien Barrau , Killian Martineau

Aspects of the full theory of loop quantum gravity can be studied in a simpler context by reducing to symmetric models like cosmological ones. This leads to several applications where loop effects play a significant role when one is…

General Relativity and Quantum Cosmology · Physics 2014-11-17 Martin Bojowald

The generalized Einstein action is treated quantum mechanically by using a quadratic lagrangian form. The canonical quantization of this action is obtained by using the auxiliary variable to define the generalized momentum. Physical…

General Physics · Physics 2009-09-30 Mahgoub Salih

A key problem in the attempt to quantize the gravitational field is the choice of boundary conditions. These are mixed, in that spatial and normal components of metric perturbations obey different sets of boundary conditions. In the…

High Energy Physics - Theory · Physics 2007-05-23 Ivan G. Avramidi , Giampiero Esposito

Dynamical black-hole scenarios have been developed in loop quantum gravity in various ways, combining results from mini and midisuperspace models. In the past, the underlying geometry of space-time has often been expressed in terms of line…

General Relativity and Quantum Cosmology · Physics 2020-09-30 Martin Bojowald

We explore the relationship between the effective dynamics in standard loop quantum cosmology (LQC) based on holonomies and triads obtained from gauge-fixing fluxes, and a modification of LQC based on holonomies and gauge-covariant fluxes…

General Relativity and Quantum Cosmology · Physics 2022-08-31 Bao-Fei Li , Parampreet Singh

The framework of the Covariant Canonical Gauge theory of Gravity (CCGG) is described in detail. CCGG emerges naturally in the Palatini formulation, where the vierbein and the spin connection are independent fields. Neither torsion nor…

General Relativity and Quantum Cosmology · Physics 2023-11-22 David Vasak , Jürgen Struckmeier

We calculate deviations in cosmological observables as a function of parameters in a class of connection-based models of quantum gravity. In this theory non-trivial modifications to the background cosmology can occur due to a distortion of…

Cosmology and Nongalactic Astrophysics · Physics 2023-02-01 Michael W. Toomey , Savvas Koushiappas , Bruno Alexandre , João Magueijo

We present a new approach to the covariant canonical formulation of Einstein-Cartan gravity that preserves the full Lorentz group as the local gauge group. The method exploits lessons learned from gravity in 2+1 dimensions regarding the…

General Relativity and Quantum Cosmology · Physics 2008-12-18 Andrew Randono

We present a first attempt to apply the approach of deformation quantization to linearized Einstein's equations. We use the analogy with Maxwell equations to derive the field equations of linearized gravity from a modified Maxwell…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Hernando Quevedo , Julio G. Tafoya

After a brief introduction to classical and quantum gravity we discuss applications of loop quantum gravity in the cosmological realm. This includes the basic formalism and recent results of loop quantum cosmology, and a computation of…

General Relativity and Quantum Cosmology · Physics 2017-08-23 Martin Bojowald , Hugo A. Morales-Tecotl

We present brief, to great extent pedagogical review on renormalization in curved space-time and of some recent results on the derivation and better understanding of quantum corrections to the action of gravity. The paper is mainly devoted…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Ilya L. Shapiro

In this thesis we consider the problem of dynamics in canonical loop quantum gravity, primarily in the context of deparametrized models, in which a scalar field is taken as a physical time variable for the dynamics of the gravitational…

General Relativity and Quantum Cosmology · Physics 2021-01-01 Ilkka Mäkinen

Loop quantum cosmology is a symmetry reduced quantization of cosmological spacetimes based on loop quantum gravity. While it has been successful in resolution of various cosmological singularities and connecting Planck scale physics to…

General Relativity and Quantum Cosmology · Physics 2019-12-25 Klaus Liegener , Parampreet Singh

This paper discusses the implementation of diffeomorphism invariance in purely Hamiltonian formulations of General Relativity. We observe that, if a constrained Hamiltonian formulation derives from a manifestly covariant Lagrangian, the…

General Relativity and Quantum Cosmology · Physics 2009-10-31 Joseph Samuel

These notes summarise a talk surveying the combinatorial or Hamiltonian quantisation of three dimensional gravity in the Chern-Simons formulation, with an emphasis on the role of quantum groups and on the way the various physical constants…

General Relativity and Quantum Cosmology · Physics 2011-05-20 Bernd J Schroers

Recent results in the construction of anomaly-free models of loop quantum gravity have shown obstacles when local physical degrees of freedom are present. Here, a set of no-go properties is derived in polarized Gowdy models, raising the…

General Relativity and Quantum Cosmology · Physics 2015-09-09 Martin Bojowald , Suddhasattwa Brahma

We suggest commutation relations for a quantum measure. In one version of these relations, the right-hand side takes account of the presence of curvature of space; in the simplest case, this yields the action of general relativity. We…

General Relativity and Quantum Cosmology · Physics 2024-01-01 Vladimir Dzhunushaliev , Vladimir Folomeev