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Related papers: Barbero-Immirzi parameter in Regge calculus

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We embed the Loop Quantum Gravity Barbero-Immirzi parameter and field within an action describing 4D, $\cal N$ = 1 supergravity and thus within a Low Energy Effective Action of Superstring/M-Theory. We use the fully gauge-covariant…

High Energy Physics - Theory · Physics 2009-09-29 S. James Gates , Sergei V. Ketov , Nicolas Yunes

The Ashtekar-Barbero-Immirzi formulation of General Relativity is extended to include spinor matter fields. Our formulation applies to generic values of the Immirzi parameter and reduces to the Ashtekar-Romano-Tate approach when the Immirzi…

General Relativity and Quantum Cosmology · Physics 2009-11-11 Simone Mercuri

The Barbero-Immirzi (BI) parameter is promoted to a field and a canonical analysis is performed when it is coupled with a Nieh-Yan topological invariant. It is shown that, in the effective theory, the BI field is a canonical pseudoscalar…

General Relativity and Quantum Cosmology · Physics 2009-07-24 Gianluca Calcagni , Simone Mercuri

This article is in the spirit of our work on the consequences of the Regge calculus, where some edge length scale arises as an optimal initial point of the perturbative expansion after functional integration over connection. Now consider…

General Relativity and Quantum Cosmology · Physics 2024-01-03 V. M. Khatsymovsky

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

We consider General Relativity as a limit case of the Scalar-Tensor theory with Barbero-Immirzi field when the field tends to a constant. We use Shapiro time delay experimental limit of $1/w = (2.1 \pm 2.3)10^{-5}$ provided by the Cassini…

General Relativity and Quantum Cosmology · Physics 2021-09-03 Leonid Perlov

We present a manifestly Lorentz-covariant description of the phase space of general relativity with the Immirzi parameter. This formulation emerges after solving the second-class constraints arising in the canonical analysis of the Holst…

General Relativity and Quantum Cosmology · Physics 2018-01-17 Merced Montesinos , Jorge Romero , Mariano Celada

We consider a loop-quantum gravity inspired modification of general relativity, where the Holst action is generalized by making the Barbero-Immirzi (BI) parameter a scalar field, whose value could be dynamically determined. The modified…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Victor Taveras , Nicolas Yunes

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

We consider minisuperspace gravity system described by piecewise flat metric discontinuous on three-dimensional faces (tetrahedra). There are infinite terms in the Einstein action. However, starting from proper regularization, these terms…

General Relativity and Quantum Cosmology · Physics 2008-10-09 V. M. Khatsymovsky

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 introduce a covariant formulation of Barbero-Immirzi connections, which are used in Loop Quantum Gravity to describe gravity. We show that Barbero-Immirzi connections can be uniquely defined out of a given spin connection for any…

Differential Geometry · Mathematics 2021-06-30 Andrea Orizzonte , Lorenzo Fatibene

A detailed canonical analysis for Pontryagin and Euler classes with a Barbero-Immirzi [BI] parameter is developed. We rewrite the topological invariants by introducing a set of Holst-like variables, and then study the set of all…

General Relativity and Quantum Cosmology · Physics 2026-04-27 Alberto Escalante , Edmundo Suárez-Polo , Luis A. Huerta-del Campo

In four dimensional gravity theory, the Barbero-Immirzi parameter has a topological origin, and can be identified as the coefficient multiplying the Nieh-Yan topological density in the gravity Lagrangian, as proposed by Date et al.[1].…

General Relativity and Quantum Cosmology · Physics 2013-07-29 Sandipan Sengupta

Regge calculus configuration superspace can be embedded into a more general superspace where the length of any edge is defined ambiguously depending on the 4-tetrahedron containing the edge. Moreover, the latter superspace can be extended…

General Relativity and Quantum Cosmology · Physics 2009-11-10 V. M. Khatsymovsky

The Regge calculus generalised to independent area tensor variables is considered. The continuous time limit is found and formal Feynman path integral measure corresponding to the canonical quantisation is written out. The quantum measure…

General Relativity and Quantum Cosmology · Physics 2009-11-07 V. M. Khatsymovsky

In the loop approach to quantum gravity the spectra of operators corresponding to such geometrical quantities as length, area and volume become quantized. However, the size of arising quanta of geometry in Planck units is not fixed by the…

General Relativity and Quantum Cosmology · Physics 2010-04-06 Kirill Krasnov

We promote the Immirzi parameter to be a minimally coupled scalar field and we analyzed the Hamiltonian constraints in the framework of Loop Quantum Gravity without the time gauge. Proper SU(2) connections can be defined and a term…

General Relativity and Quantum Cosmology · Physics 2009-11-05 Francesco Cianfrani , Giovanni Montani

The semiclassical limit of a 4-simplex amplitude for a spin foam quantum gravity model with an Immirzi parameter is studied. If the boundary state represents a non-degenerate 4-simplex geometry, the asymptotic formula contains the Regge…

General Relativity and Quantum Cosmology · Physics 2010-01-15 John W. Barrett , R. J. Dowdall , Winston J. Fairbairn , Henrique Gomes , Frank Hellmann

We study numerically the first order radiative corrections to the self-energy, in covariant loop quantum gravity. We employ the recently developed 'sl2cfoam-next' spinfoam amplitudes library, and some original numerical methods. We analyze…

General Relativity and Quantum Cosmology · Physics 2022-09-29 Pietropaolo Frisoni , Francesco Gozzini , Francesca Vidotto