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Related papers: How-To compute EPRL spin foam amplitudes

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The paper presents the new method of calculations of reaction amplitudes of processes with spin 1/2 fermions. The method is based on the application of isotropic tetrad in Minkowski space and basis spinors connected with it. We obtained as…

High Energy Physics - Phenomenology · Physics 2007-05-23 V. V. Andreev

Calculations in Loop Quantum Gravity (LQG) and spin-foams theory rely heavily on group theory of SU(2) and SL(2,C). Even though many monographs exist devoted to this theory, the different tools needed (e.g. representation theory, harmonic…

Mathematical Physics · Physics 2022-11-21 Pierre Martin-Dussaud

This thesis discusses how the pure spinor formalism can be used to efficiently compute superstring scattering amplitudes. We emphasize the pure spinor superspace form of the kinematic factors, where the simplifying features of this language…

High Energy Physics - Theory · Physics 2009-03-26 Carlos R. Mafra

We review aspects of loop quantum gravity and spin foam models at an introductory level, with special attention to questions frequently asked by non-specialists.

High Energy Physics - Theory · Physics 2008-11-26 Hermann Nicolai , Kasper Peeters

Recently a quantum group deformation of EPRL spinfoam model was proposed in arXiv:1012.4216 by one of the authors, and in arXiv:1012.4784 by Fairbairn and Meusburger. It is interesting to study the high spin asymptotics of the quantum group…

General Relativity and Quantum Cosmology · Physics 2011-03-09 You Ding , Muxin Han

The fusion coefficients from SO(3) to SO(4) play a key role in the definition of spin foam models for the dynamics in Loop Quantum Gravity. In this paper we give a simple analytic formula of the EPRL fusion coefficients. We study the large…

General Relativity and Quantum Cosmology · Physics 2013-04-30 Emanuele Alesci , Eugenio Bianchi , Elena Magliaro , Claudio Perini

In this article we review the present status of the spin foam formulation of non-perturbative (background independent) quantum gravity. The article is divided in two parts. In the first part we present a general introduction to the main…

General Relativity and Quantum Cosmology · Physics 2017-08-23 Alejandro Perez

Group field theories are particular quantum field theories defined on D copies of a group which reproduce spin foam amplitudes on a space-time of dimension D. In these lecture notes, we present the general construction of group field…

General Relativity and Quantum Cosmology · Physics 2012-10-24 Thomas Krajewski

Numerical methods in spin-foam models have significantly advanced in the last few years, yet challenges remain in efficiently extracting results for amplitudes with many quantum degrees of freedom. In this paper we sketch a proposal for a…

General Relativity and Quantum Cosmology · Physics 2023-02-22 Seth K. Asante , José Diogo Simão , Sebastian Steinhaus

We present the transition amplitude for a particle moving in a space with two times and D space dimensions having a Sp(2,R) local symmetry and an SO(D,2) rigid symmetry. It was obtained from the BRST-BFV quantization with a unique gauge…

High Energy Physics - Theory · Physics 2014-11-20 Joao E. Frederico , Victor O. Rivelles

Spin foam models are a new approach to a formulation of quantum gravity which is fully background independent, non-perturbative, and covariant, in the spirit of path integral formulations of quantum field theory. In this thesis we describe…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Daniele Oriti

In this work, we define quasicrystalline spin networks as a subspace within the standard Hilbert space of loop quantum gravity, effectively constraining the states to coherent states that align with quasicrystal geometry structures. We…

General Relativity and Quantum Cosmology · Physics 2023-06-06 Marcelo Amaral , Richard Clawson , Klee Irwin

These notes are a didactic overview of the non perturbative and background independent approach to a quantum theory of gravity known as loop quantum gravity. The definition of real connection variables for general relativity, used as a…

General Relativity and Quantum Cosmology · Physics 2009-09-29 Alejandro Perez

We study the (generalized) transition probability spaces, in the sense of Mielnik and Cantoni, for spacetime quantum states in loop quantum gravity. First, we show that loop quantum gravity admits the structures of transition probability…

General Relativity and Quantum Cosmology · Physics 2018-03-15 Xiao-Kan Guo

We consider quantum transition amplitudes, partition functions and observables for 3D spin foam models within $SU(2)$ quantum group deformation symmetry, where the deformation parameter is a complex fifth root of unity. By considering…

High Energy Physics - Theory · Physics 2022-01-13 Marcelo Amaral , Raymond Aschheim , Klee Irwin

We study the large-j asymptotics of the Euclidean EPRL/FK spin foam amplitude on a 4d simplicial complex with arbitrary number of simplices. We show that for a critical configuration (j_f, g_{ve}, n_{ef}) in general, there exists a…

General Relativity and Quantum Cosmology · Physics 2015-05-30 Muxin Han , Mingyi Zhang

The spinfoam framework is a proposal for a regularized path integral for quantum gravity. Spinfoams define quantum space-time structures describing the evolution in time of the spin network states for quantum geometry derived from Loop…

General Relativity and Quantum Cosmology · Physics 2015-03-19 Maité Dupuis

We study the transition amplitudes in state-sum models of quantum gravity in D=2,3,4 spacetime dimensions by using the field theory over a Lie group formulation. By promoting the group theory Fourier modes into creation and annihilation…

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

We present an alternative formalism for modeling spin. The ontological elements of this formalism are base-2 sequences of length $n$. The machinery necessary to model physics is then developed by considering correlations between base-2…

Quantum Physics · Physics 2022-12-15 Sam Powers , Dejan Stojkovic

Spin fluctuations have been proposed as a key mechanism for mediating superconductivity, particularly in high-temperature superconducting cuprates, where conventional electron-phonon interactions alone cannot account for the observed…

Superconductivity · Physics 2025-04-17 Griffin Heier , Sergey Y. Savrasov