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Related papers: Testing the role of the Barbero-Immirzi parameter …

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The 1-parameter family of transformations identified by Barbero and Immirzi plays a significant role in non-perturbative approaches to quantum gravity, among them Loop Quantum Gravity and Spin Foams. It facilitates the loop quantization…

General Relativity and Quantum Cosmology · Physics 2015-06-11 Bianca Dittrich , James P. Ryan

The Barbero-Immirzi parameter ($\gamma$) is introduced in loop quantum gravity (LQG) whose physical significance is still a biggest open question; because of its profound traits. In some cases, it is real-valued; while, it is complex-valued…

General Relativity and Quantum Cosmology · Physics 2022-09-22 Rakshit P. Vyas , Mihir J. Joshi

The Immirzi parameter of loop quantum gravity is a one parameter ambiguity of the theory whose precise interpretation is not universally agreed upon. It is an inherent characteristic of the quantum theory as it appears in the spectra of…

General Relativity and Quantum Cosmology · Physics 2017-06-07 Patrick J. Wong

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

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

An so(4,C)-covariant hamiltonian formulation of a family of generalized Hilbert-Palatini actions depending on a parameter (the so called Immirzi parameter) is developed. It encompasses the Ashtekar-Barbero gravity which serves as a basis of…

General Relativity and Quantum Cosmology · Physics 2014-11-17 Sergei Alexandrov

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

In this note, we review the canonical analysis of the Holst action in the time gauge, with a special emphasis on the Hamiltonian equations of motion and the fixation of the Lagrange multipliers. This enables us to identify at the…

General Relativity and Quantum Cosmology · Physics 2014-03-13 Marc Geiller , Karim Noui

We carry out the complete variational analysis of the Barbero--Immirzi--Holst Lagrangian, which is the Holst Lagrangian expressed in terms of the triad of fields $(\theta, A, \kappa)$, where $\theta$ is the solder form/spin frame, $A$ is…

General Relativity and Quantum Cosmology · Physics 2022-10-28 Andrea Orizzonte

The Barbero-Immirzi parameter $\gamma$ appears in the \emph{real} connection formulation of gravity in terms of the Ashtekar variables, and gives rise to a one-parameter quantization ambiguity in Loop Quantum Gravity. In this paper we…

General Relativity and Quantum Cosmology · Physics 2015-06-03 Tomas Liko

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

We extend the definition of the "flipped" loop-quantum-gravity vertex to the case of a finite Immirzi parameter. We cover the Euclidean as well as the Lorentzian case. We show that the resulting dynamics is defined on a Hilbert space…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Jonathan Engle , Etera Livine , Roberto Pereira , Carlo Rovelli

We consider gravity in 2+1 space-time dimensions, with negative cosmological constant and a `Barbero-Immirzi' (B-I) like parameter, when the space-time topology is of the form $ T^2 \times \mathbbm{R}$. The phase space structure, both in…

General Relativity and Quantum Cosmology · Physics 2010-05-07 Rudranil Basu , Samir K Paul

The emergence of loop quantum gravity over the past two decades has stimulated a great resurgence of interest in unifying general relativity and quantum mechanics. Amongst a number of appealing features of this approach are the intuitive…

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

The Barbero-Immirzi parameter is a one parameter quantization ambiguity underpinning the loop approach to quantum gravity that bears tantalizing similarities to the theta parameter of gauge theories such as Yang-Mills and QCD. Despite the…

High Energy Physics - Theory · Physics 2011-01-17 Simone Mercuri , Andrew Randono

In the context of the geometrical interpretation of the spin network states of Loop Quantum Gravity, we look at the holonomies of the Ashtekar-Barbero connection on loops embedded in space-like hyperboloids. We use this simple setting to…

General Relativity and Quantum Cosmology · Physics 2015-12-23 Christoph Charles , Etera R. Livine

The newly found conformal decomposition in canonical general relativity is applied to drastically simplify the recently formulated parameter-free construction of spin-gauge variables for gravity. The resulting framework preserves many of…

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

The Hamiltonian formulation of the Holst action in presence of a massless fermion field with a non-minimal Lagrangian is performed without any restriction on the local Lorentz frame. It is outlined that the phase space structure does not…

General Relativity and Quantum Cosmology · Physics 2010-04-06 F. Cianfrani , G. Montani

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

We study and compare the spectra of geometric operators (length and area) in the quantum kinematics of two formulations of three-dimensional Lorentzian loop quantum gravity. In the SU(2) Ashtekar-Barbero framework, the spectra are discrete…

General Relativity and Quantum Cosmology · Physics 2014-05-07 Jibril Ben Achour , Marc Geiller , Karim Noui , Chao Yu
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