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Related papers: Graphical calculus of spin networks

200 papers

In the past few years there has been a tumultuous activity aimed at introducing novel conceptual schemes for quantum computing. The approach proposed in (Marzuoli A and Rasetti M 2002, 2005a) relies on the (re)coupling theory of SU(2)…

Computational Complexity · Computer Science 2007-06-11 Annalisa Marzuoli , Mario Rasetti

Spin networks are at the core of quantum gravity. Our aim is to plug the mathematical community at large into the procedures turn to create a finite quantum theory of general relativity. For this, because of the different cultural…

Differential Geometry · Mathematics 2007-05-23 Andrei Tyurin

Loop Quantum Gravity defines the quantum states of space geometry as spin networks and describes their evolution in time. We reformulate spin networks in terms of harmonic oscillators and show how the holographic degrees of freedom of the…

General Relativity and Quantum Cosmology · Physics 2009-11-11 Florian Girelli , Etera R. Livine

Projected spin network states are the canonical basis of quantum states of geometry for the most recent EPR-FK spinfoam models for quantum gravity. They are functionals of both the Lorentz connection and the time normal field. We analyze in…

General Relativity and Quantum Cosmology · Physics 2014-11-21 Maité Dupuis , Etera R. Livine

In this article we propose a new construction of the spatial scalar curvature operator in (1+3)-dimensional LQG based on the twisted geometry. The starting point of the construction is to express the holonomy of the spin connection on a…

General Relativity and Quantum Cosmology · Physics 2024-12-02 Gaoping Long , Hongguang Liu

We provide a graphical method to describe and analyze non-Gaussian quantum states using a hypergraph framework. These states are pivotal resources for quantum computing, communication, and metrology, but their characterization is hindered…

Quantum Physics · Physics 2025-07-28 Lina Vandré , Boxuan Jing , Yu Xiang , Otfried Gühne , Qiongyi He

We discuss the extension of loop quantum gravity to topspin networks, a proposal which allows topological information to be encoded in spin networks. We will show that this requires minimal changes to the phase space, C*-algebra and Hilbert…

General Relativity and Quantum Cosmology · Physics 2015-06-03 Christopher L. Duston

A new link between tetrahedra and the group SU(2) is pointed out: by associating to each face of a tetrahedron an irreducible unitary SU(2) representation and by imposing that the faces close, the concept of quantum tetrahedron is seen to…

General Relativity and Quantum Cosmology · Physics 2009-10-30 A. Barbieri

A new functional calculus, developed recently for a fully non-perturbative treatment of quantum gravity, is used to begin a systematic construction of a quantum theory of geometry. Regulated operators corresponding to areas of 2-surfaces…

General Relativity and Quantum Cosmology · Physics 2010-04-06 Abhay Ashtekar , Jerzy Lewandowski

We explore the classical setting for the U(N) framework for SU(2) intertwiners for loop quantum gravity (LQG) and describe the corresponding phase space in terms of spinors with appropriate constraints. We show how its quantization leads…

General Relativity and Quantum Cosmology · Physics 2011-03-07 Enrique F. Borja , Laurent Freidel , Iñaki Garay , Etera R. Livine

Quantum computations are easily represented in the graphical notation known as the ZX-calculus, a.k.a. the red-green calculus. We demonstrate its use in reasoning about measurement-based quantum computing, where the graphical syntax…

Quantum Physics · Physics 2012-03-29 Ross Duncan

We present "Diagrams of States", a way to graphically represent and analyze how quantum information is elaborated during the execution of quantum circuits. This introductory tutorial illustrates the basics, providing useful examples of…

Quantum Physics · Physics 2009-04-20 Sara Felloni , Alberto Leporati , Giuliano Strini

We introduce a new basis on the state space of non-perturbative quantum gravity. The states of this basis are linearly independent, are well defined in both the loop representation and the connection representation, and are labeled by a…

General Relativity and Quantum Cosmology · Physics 2009-10-28 Carlo Rovelli , Lee Smolin

Hilbert space representations of quantum SU(2) by multiplication operators on a local chart are constructed, where the local chart is given by tensor products of square integrable functions on a quantum disc and on the classical unit…

Quantum Algebra · Mathematics 2018-02-20 Elmar Wagner

A visualized graph is a powerful tool for data analysis and synthesis tasks. In this case, the task of visualization constitutes not only in displaying vertices and edges according to the graph representation, but also in ensuring that the…

Combinatorics · Mathematics 2024-08-01 Sergey Kurapov , Maxim Davidovsky

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

Graphical functions have emerged as a powerful framework for evaluating multi-loop Feynman integrals in perturbative quantum field theory. Defined as massless three-point position-space integrals, they reveal rich analytic structures and…

The present paper is a short review of different path integral representations of the partition function of quantum spin systems. To begin with, I consider coherent states for SU(2) algebra. Different parameterizations of the coherent…

Strongly Correlated Electrons · Physics 2012-11-20 Naoum Karchev

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

In this paper we discuss a proposal of coherent states for Loop Quantum Gravity. These states are labeled by a point in the phase space of General Relativity as captured by a spin-network graph. They are defined as the gauge invariant…

General Relativity and Quantum Cosmology · Physics 2010-09-20 Eugenio Bianchi , Elena Magliaro , Claudio Perini