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Related papers: Loop gravity in terms of spinors

200 papers

The Hamiltonian formulation of scalar-tensor theories of gravity is derived from their Lagrangian formulation by Hamiltonian analysis. The Hamiltonian formalism marks off two sectors of the theories by the coupling parameter $\omega(\phi)$.…

General Relativity and Quantum Cosmology · Physics 2015-05-28 Xiangdong Zhang , Yongge Ma

This paper is a review of the relationship between the metric formulation of (2+1)-dimensional gravity and the loop observables of Rovelli and Smolin. I emphasize the possibility of reconstructing the geometry, via the theory of geometric…

General Relativity and Quantum Cosmology · Physics 2007-05-23 S. Carlip

Spinorial formalism is used to map every electromagnetic wave into the gravitational wave (within the linearized gravity). In this way we can obtain the gravitational counterparts of Bessel, Laguerre-Gauss, and other light beams carrying…

General Relativity and Quantum Cosmology · Physics 2016-02-17 Iwo Bialynicki-Birula , Zofia Bialynicka-Birula

The spin degrees of freedom for the relativistic particle are described by either Poincar\'{e} group variables (classically) or Grassmann variables (pseudo-classically). The relationship between those two descriptions are given. In doing…

High Energy Physics - Theory · Physics 2008-02-03 Jin-Ho Cho , Seungjoon Hyun , Jae-Kwan Kim

Loop quantum gravity is based on a classical formulation of 3+1 gravity in terms of a real SU(2) connection. Linearization of this classical formulation about a flat background yields a description of linearised gravity in terms of a {\em…

General Relativity and Quantum Cosmology · Physics 2009-11-07 Madhavan Varadarajan

The simplicial framework of Engle-Pereira-Rovelli-Livine spin-foam models is generalized to match the diffeomorphism invariant framework of loop quantum gravity. The simplicial spin-foams are generalized to arbitrary linear 2-cell…

General Relativity and Quantum Cosmology · Physics 2015-03-13 Wojciech Kamiński , Marcin Kisielowski , Jerzy Lewandowski

A new representation of Quantum Gravity is developed. This formulation is based on an extension of the group of loops. The enlarged group, that we call the Extended Loop Group, behaves locally as an infinite dimensional Lie group. Quantum…

General Relativity and Quantum Cosmology · Physics 2009-10-22 C. Di Bartolo , R. Gambini , J. Griego

In the 1960's, Mandelstam proposed a new approach to gauge theories and gravity based on loops. The program for gauge theories was completed for Yang--Mills theories by Gambini and Trias in the 1980's. Gauge theories could be understood as…

General Relativity and Quantum Cosmology · Physics 2018-10-18 Rodolfo Gambini , Jorge Pullin

We propose a new method to generate the internal isospin degree of freedom by non-local bound states. This can be seen as motivated by Bargmann-Wigner like considerations, which originated from local spin coupling. However, our approach is…

High Energy Physics - Theory · Physics 2007-05-23 Bertfried Fauser , Heinz Dehnen

Group field theories represent a 2nd quantized reformulation of the loop quantum gravity state space and a completion of the spin foam formalism. States of the canonical theory, in the traditional continuum setting, have support on graphs…

General Relativity and Quantum Cosmology · Physics 2015-02-17 Daniele Oriti , James P. Ryan , Johannes Thürigen

We point out an incompleteness of formulations of gravitational and gauge theories that use traces of holonomies around closed curves as their basic variables. It is shown that in general such loop variables have to satisfy certain…

General Relativity and Quantum Cosmology · Physics 2010-04-06 R. Loll

Loop quantum gravity has provided us with a canonical framework especially devised for background independent and diffeomorphism invariant gauge field theories. In this quantization the fundamental excitations are called spin network…

General Relativity and Quantum Cosmology · Physics 2010-09-28 Valentin Bonzom

Since the gauge group underlying 2+1-dimensional general relativity is non-compact, certain difficulties arise in the passage from the connection to the loop representations. It is shown that these problems can be handled by appropriately…

General Relativity and Quantum Cosmology · Physics 2010-04-06 A. Ashtekar , R. Loll

Spin networks are natural generalization of Wilson loops functionals. They have been extensively studied in the case where the gauge group is compact and it has been shown that they naturally form a basis of gauge invariant observables.…

High Energy Physics - Theory · Physics 2015-06-26 Laurent Freidel , Etera R. Livine

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

Loop quantum gravity envisions a small scale structure of spacetime that is markedly different from that of the classical spacetime continuum. This has ramifications for the excitation of matter fields and for their coupling to gravity.…

General Relativity and Quantum Cosmology · Physics 2021-05-19 Refik Mansuroglu , Hanno Sahlmann

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

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 show that General Relativity can be formulated as a constrained topological theory for flat 2-connections associated to the Poincar\'e 2-group. Matter can be consistently coupled to gravity in this formulation. We also show that the edge…

General Relativity and Quantum Cosmology · Physics 2013-01-15 Aleksandar Mikovic , Marko Vojinovic

Building on the universal covering group of the general linear group, we introduce the composite spinor bundle whose subbundles are Lorentz spin structures associated with different gravitational fields. General covariant transformations of…

General Relativity and Quantum Cosmology · Physics 2008-02-03 G. Giachetta , L. Mangiarotti , G. Sardanashvily