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Related papers: The twistorial structure of loop-gravity transitio…

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Using Lorentz force equation as an input a Hamiltonian mechanics on the non-projective two twistor phase space TxT is formulated. Such a construction automatically reproduces dynamics of the intrinsic classical relativistic spin. The charge…

High Energy Physics - Theory · Physics 2007-05-23 Andreas Bette

A cornerstone of the loop quantum gravity program is the fact that the phase space of general relativity on a fixed graph can be described by a product of SU(2) cotangent bundles per edge. In this paper we show how to parametrize this phase…

General Relativity and Quantum Cosmology · Physics 2010-11-11 Laurent Freidel , Simone Speziale

We demonstrate the existence of spinorial states in a theory of canonical quantum gravity without matter. This should be regarded as evidence towards the conjecture that bound states with particle properties appear in association with…

General Relativity and Quantum Cosmology · Physics 2009-10-31 M. Arnsdorf , R. S. Garcia

Spinors have played an essential but enigmatic role in modern physics since their discovery. Now that quantum-gravitational theories have started to become available, the inclusion of a description of spin in the development is natural and…

Mathematical Physics · Physics 2007-05-23 Daniel C. Galehouse

Here we argue that spinor structure arises naturally if relativistic statistical mechanics is formulated directly on phase spacetime. Requiring a first-order phase-spacetime description that retains both mass-shell branches leads to a…

Quantum Physics · Physics 2026-05-19 Mark J. Everitt

In this work we give an explicit isomorphism between the usual spin network basis and the direct quantization of the reduced phase space of tetrahedra. The main outcome is a formula that describes the space of SU(2) invariant states by an…

General Relativity and Quantum Cosmology · Physics 2010-01-15 Florian Conrady , Laurent Freidel

In this article we provide a more detailed account of the geometry and topology of the composite bundle formalism introduced by Tresguerres in Phys. Rev. D 66 (2002) 064025 [1] to accommodate gravitation as a gauge theory. In the first half…

General Relativity and Quantum Cosmology · Physics 2025-01-30 Casey Cartwright , Alex Flournoy

In the tetrad formulation of gravity, the so-called simplicity constraints play a central role. They appear in the Hamiltonian analysis of the theory, and in the Lagrangian path integral when constructing the gravity partition function from…

High Energy Physics - Theory · Physics 2021-01-25 Laurent Freidel , Marc Geiller , Daniele Pranzetti

Taking Euclidean signature space-time with its local Spin(4)=SU(2)xSU(2) group of space-time symmetries as fundamental, one can consistently gauge one SU(2) factor to get a chiral spin connection formulation of general relativity, the other…

High Energy Physics - Theory · Physics 2021-10-18 Peter Woit

We give a spinorial set of Hamiltonian variables for General Relativity in any dimension greater than 2. This approach involves a study of the algebraic properties of spinors in higher dimension, and of the elimination of second-class…

General Relativity and Quantum Cosmology · Physics 2009-10-31 James D. E. Grant

The simplicity and hidden symmetries of (Super) Yang-Mills and (Super)Gravity scattering amplitudes suggest the existence of a "weak-weak" dual formulation in which these structures are made manifest at the expense of manifest locality. We…

High Energy Physics - Theory · Physics 2015-05-13 Nima Arkani-Hamed , Freddy Cachazo , Clifford Cheung , Jared Kaplan

A review of some facts concerning classical spacetime geometry is presented together with a description of the most elementary aspects of the two-component spinor formalisms of Infeld and van der Waerden. Special attention is concentrated…

Mathematical Physics · Physics 2016-12-22 Jorge G. Cardoso

The kinematics of loop gravity can be given a manifestly Lorentz-covariant formulation: the conventional SU(2)-spin-network Hilbert space can be mapped to a space K of SL(2,C) functions, where Lorentz covariance is manifest. K can be…

General Relativity and Quantum Cosmology · Physics 2011-05-25 Carlo Rovelli , Simone Speziale

We give a self-contained derivation of the MHV amplitudes for gravity and use the associated twistor generating function to define a twistor action for the MHV diagram approach to gravity. Starting from a background field calculation on a…

High Energy Physics - Theory · Physics 2014-11-18 Lionel Mason , David Skinner

A covariant spin-foam formulation of quantum gravity has been recently developed, characterized by a kinematics which appears to match well the one of canonical loop quantum gravity. In this paper we reconsider the implementation of the…

General Relativity and Quantum Cosmology · Physics 2014-11-21 You Ding , Carlo Rovelli

Within the framework of spinfoam models, we revisit the simplicity constraints reducing topological BF theory to 4d Riemannian gravity. We use the reformulation of SU(2) intertwiners and spin networks in term of spinors, which has come out…

General Relativity and Quantum Cosmology · Physics 2015-05-27 Maité Dupuis , Etera R. Livine

We show that the path integral for the three-dimensional SU(2) BF theory with a Wilson loop or a spin network function inserted can be understood as the Rovelli-Smolin loop transform of a wavefunction in the Ashtekar connection…

General Relativity and Quantum Cosmology · Physics 2009-01-16 A. Mikovic

Simplicial versions of topological abelian gauge theories are constructed which reproduce the continuum expressions for the partition function and Wilson expectation value of linked loops, expressible in terms of R-torsion and linking…

High Energy Physics - Theory · Physics 2008-02-03 David H. Adams

We provide the Barrett-Crane spin foam model for quantum gravity with a discrete action principle, consisting in the usual BF term with discretized simplicity constraints which in the continuum turn topological BF theory into gravity. The…

General Relativity and Quantum Cosmology · Physics 2009-11-06 Valentin Bonzom , Etera R. Livine

In the context of a canonical quantization of general relativity, one can deform the loop gravity phase space on a graph by replacing the T*SU(2) phase space attached to each edge by SL(2,C) seen as a phase space. This deformation is…

General Relativity and Quantum Cosmology · Physics 2016-03-08 Maité Dupuis , Florian Girelli , Etera R. Livine