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Related papers: Global Barbero-Immirzi Connections

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The Barbero-Immirzi (BI) connection, as usually introduced out of a spin connection, is a global object though it does not transform properly as a genuine connection with respect to generic spin transformations, unless quite specific and…

General Relativity and Quantum Cosmology · Physics 2008-11-26 L. Fatibene , M. Francaviglia , C. Rovelli

We shall present here a general apt technique to induce connections along bundle reductions which is different from the standard restriction. This clarifies and generalizes the standard procedure to define Barbero-Immirzi (BI) connection,…

General Relativity and Quantum Cosmology · Physics 2013-05-29 L. Fatibene , M. Ferraris , M. Francaviglia

We shall show that no reductive splitting of the spin group exists in dimension 3 \leq m \leq 20 other than in dimension m = 4. In dimension 4 there are reductive splittings in any signature. Euclidean and Lorentzian signatures are reviewed…

General Relativity and Quantum Cosmology · Physics 2012-06-19 L. Fatibene , M. Francaviglia , S. Garruto

We shall here discuss a new spacetime gauge-covariant Lagrangian formulation of General Relativity by means of the Barbero-Immirzi SU(2)-connection on spacetime. To the best of our knowledge the Lagrangian based on SU(2) spacetime fields…

General Relativity and Quantum Cosmology · Physics 2008-11-26 L. Fatibene , M. Francaviglia , C. Rovelli

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

In Loop Quantum Gravity the classical point of departure is the Einstein-Hilbert action modified by the addition of the so-called Holst term. Classically, this term does not affect the equations of motion, but it induces a well-known…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Simone Mercuri , Victor Taveras

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

We aim to provide a rigorous geometric framework for the Ashtekar-Barbero-Immirzi formulation of General Relativity. As the starting point of this formulation consists in recasting General Relativity as an SU(2) gauge theory, it naturally…

General Relativity and Quantum Cosmology · Physics 2025-05-26 Matteo Bruno

This letter is a critique of Barbero's constrained Hamiltonian formulation of General Relativity on which current work in Loop Quantum Gravity is based. While we do not dispute the correctness of Barbero's formulation of general relativity,…

General Relativity and Quantum Cosmology · Physics 2010-04-06 Joseph Samuel

The Bargmann-Wigner (BW) scalar product is a particular case of a larger class of scalar products parametrized by a family of world-vectors. The choice of null and $p$-dependent world-vectors leads to BW amplitudes which behave as local…

Quantum Physics · Physics 2007-05-23 Marek Czachor

Covariant loop gravity comes out of the canonical analysis of the Palatini action and the use of the Dirac brackets arising from dealing with the second class constraints (``simplicity'' constraints). Within this framework, we underline a…

General Relativity and Quantum Cosmology · Physics 2014-11-17 Sergei Alexandrov , Etera R. Livine

We study the role of the Barbero-Immirzi parameter $\gamma$ and the choice of connection in the construction of (a symmetry-reduced version of) loop quantum gravity. We start with the four-dimensional Lorentzian Holst action that we reduce…

General Relativity and Quantum Cosmology · Physics 2015-05-19 Jibril Ben Achour , Marc Geiller , Karim Noui , Chao Yu

In this manuscript, we aim to classify and characterize the moduli space of homogeneous spin connections and homogeneous SU(2) connections on three-dimensional Riemannian homogeneous spaces. An analysis of the topology of the associated…

Mathematical Physics · Physics 2025-09-23 Matteo Bruno , Gabriele Peluso

We present a histories version of the connection formalism of general relativity. Such an approach introduces a spacetime description--a characteristic feature of the histories approach--and we discuss the extent to which the usual loop…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Ntina Savvidou

The Immirzi parameter is promoted to be a scalar field and the Hamiltonian analysis of the corresponding dynamical system is performed in the presence of gravity. We identified some SU(2) connections, generalizing Ashtekar-Barbero…

General Relativity and Quantum Cosmology · Physics 2016-09-14 Flavio Bombacigno , Francesco Cianfrani , Giovanni Montani

The Ashtekar-Barbero formulation of general relativity admits a one-parameter family of canonical transformations that preserves the expressions of the Gauss and diffeomorphism constraints. The loop quantization of the connection formalism…

General Relativity and Quantum Cosmology · Physics 2010-04-06 Guillermo A. Mena Marugan

We present a parameter-free gauge formulation of general relativity in terms of a new set of real spin connection variables. The theory is constructed by extending the phase space of the recently formulated conformal geometrodynamics for…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Charles H. -T. Wang

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

We generalise the study of constraints imposed by supersymmetry on the Berry connection to transformations with component fields in representations of an internal symmetry group G. Since the fields act as co-ordinates of the underlying…

High Energy Physics - Theory · Physics 2010-06-11 Gianni Tallarita

Projected spin network states are the canonical basis of quantum states of geometry for the most recent EPR-FK spinfoam models for quantum gravity. They are functionals of both the Lorentz connection and the time normal field. We analyze in…

General Relativity and Quantum Cosmology · Physics 2014-11-21 Maité Dupuis , Etera R. Livine
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