English
Related papers

Related papers: Observables in Loop Quantum Gravity with a cosmolo…

200 papers

3D Loop Quantum Gravity with a vanishing cosmological constant can be related to the quantization of the $\textrm{SU}(2)$ BF theory discretized on a lattice. At the classical level, this discrete model characterizes discrete flat geometries…

General Relativity and Quantum Cosmology · Physics 2014-12-03 Valentin Bonzom , Maité Dupuis , Florian Girelli

The problem of background independent quantum gravity is the problem of defining a quantum field theory of matter and gravity in the absence of an underlying background geometry. Loop quantum gravity (LQG) is a promising proposal for…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Alejandro Perez

In this paper we report some results on the expectation values of a set of observables introduced for 3-dimensional Riemannian quantum gravity with positive cosmological constant, that is, observables in the Turaev-Viro model. Instead of…

General Relativity and Quantum Cosmology · Physics 2009-11-10 J. Manuel Garcia-Islas

Motivated by a recent proposal (by Koslowski-Sahlmann) of a kinematical representation in Loop Quantum Gravity (LQG) with a nondegenerate vacuum metric, we construct a polymer quantization of the parametrised massless scalar field theory on…

General Relativity and Quantum Cosmology · Physics 2013-09-12 Sandipan Sengupta

Working within the framework of Loop Quantum Gravity (LQG), we construct a set of three operators suitable for identifying coordinate-like quantities on a spin-network configuration. In doing so, we rely on known properties of operators for…

High Energy Physics - Theory · Physics 2018-07-19 Suddhasattwa Brahma , Antonino Marcianò , Michele Ronco

One of the celebrated results of Loop Quantum Gravity (LQG) is the discreteness of the spectrum of geometrical operators such as length, area and volume operators. This is an indication that Planck scale geometry in LQG is discontinuous…

General Relativity and Quantum Cosmology · Physics 2009-02-10 Bianca Dittrich , Thomas Thiemann

The implementation of the dynamics in Loop Quantum Gravity (LQG) is still an open problem. Here, we discuss a tentative dynamics for the simplest class of graphs in LQG: Two vertices linked with an arbitrary number of edges. We use the…

General Relativity and Quantum Cosmology · Physics 2015-05-20 Enrique F. Borja , Jacobo Díaz-Polo , Iñaki Garay , Etera R. Livine

Gauge-invariant observables for quantum gravity are described, with explicit constructions given primarily to leading order in Newton's constant, analogous to and extending constructions first given by Dirac in quantum electrodynamics.…

High Energy Physics - Theory · Physics 2016-07-19 William Donnelly , Steven B. Giddings

We consider a deformation of 3D lattice gauge theory in the canonical picture, first classically, based on the Heisenberg double of $\operatorname{SU}(2)$, then at the quantum level. We show that classical spinors can be used to define a…

High Energy Physics - Lattice · Physics 2023-02-01 Valentin Bonzom , Maïté Dupuis , Florian Girelli , Qiaoyin Pan

We present a reformulation of loop quantum gravity with a cosmological constant and no matter as a Fermi-liquid theory. When the topological sector is deformed and large gauge symmetry is broken, we show that the Chern-Simons state reduces…

High Energy Physics - Theory · Physics 2008-12-18 Stephon H. S. Alexander , Gianluca Calcagni

We further develop a noncommutative model unifying quantum mechanics and general relativity proposed in {\it Gen. Rel. Grav.} (2004) {\bf 36}, 111-126. Generalized symmetries of the model are defined by a groupoid $\Gamma $ given by the…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Leszek Pysiak , Michael Heller , Zdzislaw Odrzygozdz , Wieslaw Sasin

A rigorous implementation of the Wheeler-Dewitt equations was derived in the context of Loop Quantum Gravity (LQG) and was coined Quantum Spin Dynamics (QSD). The Hamiltonian constraint of QSD was criticised as being too local and to…

General Relativity and Quantum Cosmology · Physics 2021-12-09 Thomas Thiemann , Madhavan Varadarajan

We apply the full theory of Loop Quantum Gravity (LQG) to cosmology and present a top-down derivation of gauge-invariant cosmological perturbation theory from quantum gravity. The derivation employs the reduced phase space formulation of…

General Relativity and Quantum Cosmology · Physics 2021-01-20 Muxin Han , Haida Li , Hongguang Liu

We perform a canonical, reduced phase space quantisation of General Relativity by Loop Quantum Gravity (LQG) methods. The explicit construction of the reduced phase space is made possible by the combination of 1. the Brown -- Kuchar…

General Relativity and Quantum Cosmology · Physics 2014-11-18 K. Giesel , T. Thiemann

In this paper, I investigate the possible quantization, in the context of LQG, of three dimensional gravity in the case of positive cosmological constant {\Lambda} and try to make contact with alternative quantization approaches already…

General Relativity and Quantum Cosmology · Physics 2012-08-15 Daniele Pranzetti

Using a new procedure based on Kummer's Confluent Hypergeometric Functions, we investigate the question of singularity avoidance in loop quantum gravity (LQG) in the context of U$(1)^3$ complexifier coherent states and compare obtained…

General Relativity and Quantum Cosmology · Physics 2021-09-16 Kristina Giesel , David Winnekens

These notes are a didactic overview of the non perturbative and background independent approach to a quantum theory of gravity known as loop quantum gravity. The definition of real connection variables for general relativity, used as a…

General Relativity and Quantum Cosmology · Physics 2009-09-29 Alejandro Perez

Loop Quantum Gravity (LQG) is a non-perturbative attempt at quantization of a classical phase space description of gravity in terms of $SU(2)$ connections and electric fields. As emphasized recently [1], on this phase space, classical…

General Relativity and Quantum Cosmology · Physics 2021-07-07 Madhavan Varadarajan

The essential features of a quantum group deformation of classical symmetries of General Relativity in the case with non-vanishing cosmological constant $\Lambda$ are presented. We fully describe (anti-)de Sitter non-commutative spacetimes…

High Energy Physics - Theory · Physics 2020-03-10 Ivan Gutierrez-Sagredo , Angel Ballesteros , Giulia Gubitosi , Francisco J. Herranz

This series of lectures gives a simple and self-contained introduction to the non-perturbative and background independent loop approach of canonical quantum gravity. The Hilbert space of kinematical quantum states is constructed and a…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Marcus Gaul , Carlo Rovelli