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Related papers: A Immirzi-like parameter for 3d quantum gravity

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We clarify the role played by the Immirzi parameter in classical gravity coupled to fermions. Considering the general non-minimal coupling, we show that, although the torsion depends explicitly on the Immirzi parameter, in a suitable…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Sergei Alexandrov

We investigate the consequences of the ambiguity of minimal coupling procedure for Einstein-Cartan gravity with Holst term and fermions. A new insight is provided into the nature and physical relevance of coupling procedures considered…

General Relativity and Quantum Cosmology · Physics 2009-12-11 Marcin Kaźmierczak

In this paper we generalise previous work on tensor perturbations in a de Sitter background in terms of Ashtekar variables to cover all complex values of the Immirzi parameter gamma (previous work was restricted to imaginary gamma).…

General Relativity and Quantum Cosmology · Physics 2015-05-30 Laura Bethke , Joao Magueijo

Canonical quantum gravity provides insights into the quantum dynamics as well as quantum geometry of space-time by its implications for constraints. Loop quantum gravity in particular requires specific corrections due to its quantization…

General Relativity and Quantum Cosmology · Physics 2015-05-14 Martin Bojowald

In order to study 3d loop quantum gravity coupled to matter, we consider a simplified model of abelian quantum gravity, the so-called U(1)^3 model. Abelian gravity coupled to a scalar field shares a lot of commonalities with parameterized…

General Relativity and Quantum Cosmology · Physics 2019-05-01 Christoph Charles

In this letter we have shown that a possible connection between the LQG Immirzi parameter and the area of a punctured surface can emerge depending on the thermostatistics theory previously chosen. Starting from the Boltzmann-Gibbs entropy,…

General Relativity and Quantum Cosmology · Physics 2018-12-26 Everton M. C. Abreu , Jorge Ananias Neto , Albert C. R. Mendes , Rodrigo M. de Paula

We use the mathematical framework of loop quantum gravity (LQG) to study the quantization of three dimensional (Riemannian) gravity with positive cosmological constant (Lambda>0). We show that the usual regularization techniques (successful…

General Relativity and Quantum Cosmology · Physics 2014-11-20 Alejandro Perez , Daniele Pranzetti

We present a novel approach to quantizing the length in noncommutative spaces with positional-dependent noncommutativity. The method involves constructing ladder operators that change the length not only along a plane but also along the…

High Energy Physics - Theory · Physics 2024-07-11 Jishnu Aryampilly , Muthukumar Balasundaram , Aamir Rashid

We shall here perform the canonical analysis of field equations of ABI model in order to determine constraint equations. We shall show that one can use algebraic constraints in the covariant framework to fix $k^i$ as a function of the frame…

General Relativity and Quantum Cosmology · Physics 2026-02-05 L. Fatibene , A. Orizzonte

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

A general nonperturvative loop quantization procedure for metric modified gravity is reviewed. As an example, this procedure is applied to scalar-tensor theories of gravity. The quantum kinematical framework of these theories is rigorously…

General Relativity and Quantum Cosmology · Physics 2013-04-09 Xiangdong Zhang , Yongge Ma

Existence of a minimal measurable length, as an effective cutoff in the ultraviolet regime, is a common feature of all approaches to the quantum gravity proposal. It is widely believed that this length scale will be of the order of the…

General Relativity and Quantum Cosmology · Physics 2016-05-04 K. Nozari , M. Khodadi , M. A. Gorji

Holst action containing Immirzi parameter for pure gravity is generalised to the supergravity theories. Supergravity equations of motion are not modified by such generalisations, thus preserving supersymmetry. Dependence on the Immirzi…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Romesh K. Kaul

It is natural to ask whether non-commutative geometry plays a role in four dimensional physics. By performing explicit computations in various toy models, we show that quantum effects lead to violations of Lorentz invariance at the level of…

High Energy Physics - Phenomenology · Physics 2009-11-07 Alexey Anisimov , Tom Banks , Michael Dine , Michael Graesser

We describe a deformation of the observable algebra of quantum gravity in which the loop algebra is extended to framed loops. This allows an alternative nonperturbative quantization which is suitable for describing a phase of quantum…

General Relativity and Quantum Cosmology · Physics 2009-09-25 Seth Major , Lee Smolin

We study the coupling of the gravitational action, which is a linear combination of the Hilbert-Palatini term and the quadratic torsion term, to the action of Dirac fermions. The system possesses local Poincare invariance and hence belongs…

General Relativity and Quantum Cosmology · Physics 2013-10-02 Jian Yang , Kinjal Banerjee , Yongge Ma

A simple model is constructed which allows to compute modified dispersion relations with effects from loop quantum gravity. Different quantization choices can be realized and their effects on the order of corrections studied explicitly. A…

General Relativity and Quantum Cosmology · Physics 2016-08-31 Martin Bojowald , Hugo A. Morales-Tecotl , Hanno Sahlmann

A detailed Dirac's and Faddeev-Jackiw quantization of Bonzom-Livine model describing gravity in three dimensions is performed. The full structure of the constraints, the gauge transformations and the generalized Faddeev-Jackiw brackets are…

Mathematical Physics · Physics 2016-11-08 Alberto Escalante , Jaime Manuel Cabrera

In a previous work [arXiv:2009.03428] we proposed a new model for Quantum GRavity(QGR) and cosmology, dubbed $SU(\infty)$-QGR. One of the axioms of this model is that Hilbert spaces of the Universe and its subsystems represent $SU(\infty)$…

General Relativity and Quantum Cosmology · Physics 2022-01-04 Houri Ziaeepour

The possibility of a minimal physical length in quantum gravity is discussed within the asymptotic safety approach. Using a specific mathematical model for length measurements ("COM microscope") it is shown that the spacetimes of Quantum…

High Energy Physics - Theory · Physics 2008-11-26 Martin Reuter , Jan-Markus Schwindt