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Related papers: LQG vertex with finite Immirzi parameter

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We reconsider the Rovelli-Smolin model of gravity coupled to the Klein-Gordon time field with an eye towards capturing the degrees of freedom of the scalar field lost in the framework in which time is deparametrized by the scalar field.…

General Relativity and Quantum Cosmology · Physics 2016-02-03 Jerzy Lewandowski , Hanno Sahlmann

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 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

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

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 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

We compute the transition amplitude between coherent quantum-states of geometry peaked on homogeneous isotropic metrics. We use the holomorphic representations of loop quantum gravity and the Kaminski-Kisielowski-Lewandowski generalization…

General Relativity and Quantum Cosmology · Physics 2010-10-27 Eugenio Bianchi , Carlo Rovelli , Francesca Vidotto

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

This series of lectures gives a simple and self-contained introduction to the non-perturbative and background independent loop approach of canonical quantum gravity. The Hilbert space of kinematical quantum states is constructed and a…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Marcus Gaul , Carlo Rovelli

We define a modification of LQG in which graphs are required to consist in piecewise linear edges, which we call piecewise linear LQG (plLQG). At the diffeomorphism invariant level, we prove that plLQG is equivalent to standard LQG, as long…

General Relativity and Quantum Cosmology · Physics 2010-01-21 Jonathan Engle

In this work, it is demonstrated how the kinematical Hilbert space of Loop Quantum Gravity (LQG) can be inferred from the configuration space of BF theories via the imposition of the Hamiltonian constraints. In particular, it is outlined…

General Relativity and Quantum Cosmology · Physics 2015-05-20 Francesco Cianfrani

We construct in this article a new realization of quantum geometry, which is obtained by quantizing the recently-introduced flux formulation of loop quantum gravity. In this framework, the vacuum is peaked on flat connections, and states…

General Relativity and Quantum Cosmology · Physics 2021-06-18 Benjamin Bahr , Bianca Dittrich , Marc Geiller

We review the canonical analysis of the Palatini action without going to the time gauge as in the standard derivation of Loop Quantum Gravity. This allows to keep track of the Lorentz gauge symmetry and leads to a theory of Covariant Loop…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Etera R. Livine

We introduce a new framework for loop quantum gravity: mimicking the spinfoam quantization procedure we propose to study the symmetric sectors of the theory imposing the reduction weakly on the full kinematical Hilbert space of the…

General Relativity and Quantum Cosmology · Physics 2015-06-12 Emanuele Alesci , Francesco Cianfrani

I describe a possible perspective on the current state of loop quantum gravity, at the light of the developments of the last years. I point out that a theory is now available, having a well-defined background-independent kinematics and a…

General Relativity and Quantum Cosmology · Physics 2011-05-25 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

We argue in a model-independent way that the Hilbert space of quantum gravity is locally finite-dimensional. In other words, the density operator describing the state corresponding to a small region of space, when such a notion makes sense,…

High Energy Physics - Theory · Physics 2017-11-22 Ning Bao , Sean M. Carroll , Ashmeet Singh

We discuss the semiclassical limit of Quantum Reduced Loop Gravity, a recently proposed model to address the quantum dynamics of the early Universe. We apply the techniques developed in full Loop Quantum Gravity to define the semiclassical…

General Relativity and Quantum Cosmology · Physics 2015-06-18 Emanuele Alesci , Francesco Cianfrani

This letter is motivated by the recent papers by Dittrich and Thiemann and, respectively, by Rovelli discussing the status of Quantum Geometry in the dynamical sector of Loop Quantum Gravity. Since the papers consider model examples, we…

General Relativity and Quantum Cosmology · Physics 2008-11-07 Wojciech Kaminski , Jerzy Lewandowski , Lukasz Szulc

Spin foam models, an approach to defining the dynamics of loop quantum gravity, make use of the Plebanski formulation of gravity, in which gravity is recovered from a topological field theory via certain constraints called simplicity…

General Relativity and Quantum Cosmology · Physics 2016-09-14 Jonathan Engle , Antonia Zipfel