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Related papers: Polyhedra in loop quantum gravity

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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

We introduce semiclassical methods into the study of the volume spectrum in loop gravity. The classical system behind a 4-valent spinnetwork node is a Euclidean tetrahedron. We investigate the tetrahedral volume dynamics on phase space and…

General Relativity and Quantum Cosmology · Physics 2014-02-19 Eugenio Bianchi , Hal M. Haggard

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

In this note we present preliminary study on the relation between the quantum entanglement of boundary states and the quantum geometry in the bulk in the framework of spin networks. We conjecture that the emergence of space with non-zero…

High Energy Physics - Theory · Physics 2019-10-25 Yi Ling , Yikang Xiao , Meng-He Wu

In a spin-network basis state, nodes of the graph describe un-entangled quantum regions of space, quantum polyhedra. In this paper we show how entanglement between intertwiner degrees of freedom enforces gluing conditions for neighboring…

General Relativity and Quantum Cosmology · Physics 2018-07-04 Bekir Baytaş , Eugenio Bianchi , Nelson Yokomizo

We present a generalization of Minkowski's classic theorem on the reconstruction of tetrahedra from algebraic data to homogeneously curved spaces. Euclidean notions such as the normal vector to a face are replaced by Levi-Civita holonomies…

Mathematical Physics · Physics 2017-02-15 Hal M. Haggard , Muxin Han , Aldo Riello

I discuss the role played by the spin-network basis and recoupling theory (in its graphical tangle-theoretic formulation) and their use for performing explicit calculations in loop quantum gravity. In particular, I show that recoupling…

General Relativity and Quantum Cosmology · Physics 2009-10-30 Roberto De Pietri

The standard toolkit of operators to probe quanta of geometry in loop quantum gravity consists in area and volume operators as well as holonomy operators. New operators have been defined, in the U(N) framework for intertwiners, which allow…

General Relativity and Quantum Cosmology · Physics 2018-10-24 Christophe Goeller , Etera R. Livine

We describe the Lorentzian version of the Kapovitch-Millson phase space for polyhedra with $N$ faces. Starting with the Schwinger representation of the $\mathfrak{su}(1,1)$ Lie algebra in terms of a pair of complex variables (or spinor), we…

Mathematical Physics · Physics 2019-01-30 Etera R. Livine

We investigate the geometry of the space of N-valent SU(2)-intertwiners. We propose a new set of holomorphic operators acting on this space and a new set of coherent states which are covariant under U(N) transformations. These states are…

General Relativity and Quantum Cosmology · Physics 2015-05-18 Laurent Freidel , Etera R. Livine

In Loop Quantum Gravity, the quantum action of the volume operator is crucial in understanding quantum dynamics. In this work, we implement a generalized numerical algorithm that can compute the quantum action of the volume operator on a…

General Relativity and Quantum Cosmology · Physics 2026-04-01 Haida Li , Hongguang Liu

Quantum geometry, i.e., the quantum theory of intrinsic and extrinsic spatial geometry, is a cornerstone of loop quantum gravity. Recently, there have been many new ideas in this field, and I will review some of them. In particular, after a…

General Relativity and Quantum Cosmology · Physics 2015-06-03 Hanno Sahlmann

In this work, we investigate the 4d path integral for Euclidean quantum gravity on a hypercubic lattice, as given by the Spin Foam model by Engle, Pereira, Rovelli, Livine, Freidel and Krasnov (EPRL-FK). To tackle the problem, we restrict…

General Relativity and Quantum Cosmology · Physics 2016-05-25 Benjamin Bahr , Sebastian Steinhaus

We investigate the construction of coherent states for quantum theories of connections based on graphs embedded in a spatial manifold, as in loop quantum gravity. We discuss the many subtleties of the construction, mainly related to the…

General Relativity and Quantum Cosmology · Physics 2015-06-04 Daniele Oriti , Roberto Pereira , Lorenzo Sindoni

While general relativity provides a complete geometric theory of gravity, it fails to explain the other three forces of nature, i.e., electromagnetism and weak and strong interactions. We require the quantum field theory (QFT) to explain…

General Relativity and Quantum Cosmology · Physics 2023-04-11 Santanu Das

Black hole entropy is one of the few windows toward the quantum aspects of gravitation and its study over the years have highlighted the holographic nature of gravity. At the non-perturbative level in quantum gravity, promising explanations…

General Relativity and Quantum Cosmology · Physics 2018-02-14 Alexandre Feller , Etera R. Livine

The building blocks of a quantum theory of general relativity are expected to be discrete structures. Loop quantum gravity is formulated using a basis of spin networks (wave functions over oriented graphs with coloured edges), thus…

General Relativity and Quantum Cosmology · Physics 2015-06-17 Jacobo Diaz-Polo , Iñaki Garay

The Lasserre's reconstruction algorithm is extended to the D-polytopes with the construction of their shape space. Thus, the areas of d-skeletons $(1\leq d\leq D)$ can be expressed as functions of the areas and normal bi-vectors of the…

General Relativity and Quantum Cosmology · Physics 2022-01-19 Gaoping Long , Yongge Ma

The study of toy models in loop quantum gravity (LQG), defined as truncations of the full theory, is relevant to both the development of the LQG phenomenology, in cosmology and astrophysics, and the progress towards the resolution of the…

General Relativity and Quantum Cosmology · Physics 2022-07-13 Eneko Aranguren , Iñaki Garay , Etera R. Livine

In the loop quantum gravity framework, spin network states carry entanglement between quantum excitations of the geometry at different space points. This intertwiner entanglement is gauge-invariant and comes from quantum superposition of…

General Relativity and Quantum Cosmology · Physics 2022-10-19 Qian Chen , Etera R. Livine