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The Barbero-Immirzi parameter $\gamma$ appears as a coupling constant in the spinfoam dynamics of loop quantum gravity. In this work, we highlight that $\gamma$ can be understood as a measure of gravitational parity violation via a duality…

General Relativity and Quantum Cosmology · Physics 2026-04-28 Eugenio Bianchi , Monica Rincon-Ramirez

It is argued that quantum gravity has an interpretation as a topological field theory provided a certain constraint from the path intergral measure is respected. The constraint forces us to couple gauge and matter fields to gravity for…

High Energy Physics - Theory · Physics 2009-10-30 Andrew Toon

We construct and study Loop Quantum Cosmology (LQC) when the Barbero-Immirzi parameter takes the complex value $\gamma=\pm i$. We refer to this new quantum cosmology as complex Loop Quantum Cosmology. We proceed in making an analytic…

General Relativity and Quantum Cosmology · Physics 2015-06-22 Jibril Ben Achour , Julien Grain , Karim Noui

We investigate the canonical quantization of gravity coupled to pointlike matter in 2+1 dimensions. Starting from the usual point particle action in the first order formalism, we introduce auxiliary variables which make the action locally…

High Energy Physics - Theory · Physics 2008-11-26 Daniel Kabat , Miguel Ortiz

We show that the non-Abelian nature of geometric fluxes---the corner-stone in the definition of quantum geometry in the framework of loop quantum gravity (LQG)---follows directly form the continuum canonical commutations relations of…

General Relativity and Quantum Cosmology · Physics 2020-02-03 Alberto S. Cattaneo , Alejandro Perez

The canonical analysis of the (anti-) self-dual action for gravity supplemented with the (anti-) self-dual Pontrjagin term is carried out. The effect of the topological term is to add a `magnetic' term to the original momentum variable…

General Relativity and Quantum Cosmology · Physics 2009-11-07 Merced Montesinos

We here conjecture that two much-studied aspects of quantum gravity, dimensional flow and spacetime fuzziness, might be deeply connected. We illustrate the mechanism, providing first evidence in support of our conjecture, by working within…

High Energy Physics - Theory · Physics 2017-11-15 Giovanni Amelino-Camelia , Gianluca Calcagni , Michele Ronco

In this PhD thesis, we introduced a new strategy to investigate the kinematical and physical predictions of self dual Loop Quantum Gravity (LQG) and by-passed the old problem of implementing quantum mechanically the so called reality…

General Relativity and Quantum Cosmology · Physics 2015-11-24 Jibril Ben Achour

We study the euclidean covariant loop-quantum-gravity vertex numerically, using a cylindrically symmetric boundary state and a convenient value of the Barbero-Immirzi parameter. We show that a classical geometry emerges already at low spin.…

General Relativity and Quantum Cosmology · Physics 2016-03-28 Vincent Bayle , François Collet , Carlo Rovelli

We conjecture that the modified commutation relations suggested in the context of quantum gravity (QG) persist also in the classical limit, if the momentum of the classical object is not too large, and calculate the corresponding perihelion…

General Relativity and Quantum Cosmology · Physics 2009-07-24 Z. K. Silagadze

Starting from a Lagrangian we perform the full constraint analysis of the Hamiltonian for General relativity in the tetrad-connection formulation for an arbitrary value of the Immirzi parameter and solve the second class constraints,…

General Relativity and Quantum Cosmology · Physics 2009-10-31 Nuno Barros e Sa

We recast the finite-region analysis of Einstein's equations that underpins the ER=EPR program into the loop quantum gravity (LQG) framework. By translating curvature-energy uncertainty relations into holonomy-flux kinematics, and by…

General Relativity and Quantum Cosmology · Physics 2025-08-29 Fabrizio Tamburini

In this paper we analyze the functional renormalization group flow of quantum gravity on the Einstein-Cartan theory space. The latter consists of all action functionals depending on the spin connection and the vielbein field (co-frame)…

High Energy Physics - Theory · Physics 2015-06-12 Jan-Eric Daum , Martin Reuter

We study the algebra of constraints of quantum gravity in the loop representation based on Ashtekar's new variables. We show by direct computation that the quantum commutator algebra reproduces the classical Poisson bracket one, in the…

General Relativity and Quantum Cosmology · Physics 2009-10-22 Rodolfo Gambini , Alcides Garat , Jorge Pullin

We study the derivation of the effective equation of motion for a pointlike particle in the framework of quantum gravity. Just like the geodesic motion of a classical particle is a consequence of classical field theory coupled to general…

General Relativity and Quantum Cosmology · Physics 2019-10-01 Francisco Pipa , Nikola Paunkovic , Marko Vojinovic

We present the Hamiltonian formulation of General Relativity with the Holst formulation in a generic local Lorentz frame. In particular, we outline that a Gauss constraint is inferred by a proper generalization of Ashtekar-Barbero-Immirzi…

General Relativity and Quantum Cosmology · Physics 2009-04-06 Francesco Cianfrani , Giovanni Montani

In the framework of loop quantum cosmology anomaly free quantizations of the Hamiltonian constraint for Bianchi class A, locally rotationally symmetric and isotropic models are given. Basic ideas of the construction in (non-symmetric) loop…

General Relativity and Quantum Cosmology · Physics 2009-10-31 Martin Bojowald

We show that there exists a divergent correlation length in 2d quantum gravity for the matter fields close to the critical point provided one uses the invariant geodesic distance as the measure of distance. The corresponding…

High Energy Physics - Lattice · Physics 2009-10-30 J. Ambjorn , K. N. Anagnostopoulos

3-dimensional gravity coupled to Maxwell (or Klein-Gordon) fields is exactly soluble under the assumption of axi-symmetry. The solution is used to probe several quantum gravity issues. In particular, it is shown that the quantum…

General Relativity and Quantum Cosmology · Physics 2009-10-28 Abhay Ashtekar

Quantum gravity theories predict a minimal length at the order of magnitude of the Planck length, under which the concepts of space and time lose every physical meaning. In quantum mechanics, the insurgence of such minimal length can be…

Quantum Physics · Physics 2016-07-08 Matteo A. C. Rossi , Tommaso Giani , Matteo G. A. Paris