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Related papers: A Topos Model for Loop Quantum Gravity

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Loop quantum gravity is believed to eliminate singularities such as the big bang and big crunch singularity. This belief is based on studies of so-called loop quantum cosmology which concerns symmetry-reduced models of quantum gravity. In…

General Relativity and Quantum Cosmology · Physics 2017-09-12 Ward Struyve

We comment on structural properties of the algebras $\mathfrak{A}_{LQG/LQC}$ underlying loop quantum gravity and loop quantum cosmology, especially the representation theory, relating the appearance of the (dynamically induced)…

General Relativity and Quantum Cosmology · Physics 2015-04-10 Alexander Stottmeister , Thomas Thiemann

We define a modification of LQG in which graphs are required to consist in piecewise linear edges, which we call piecewise linear LQG (plLQG). At the diffeomorphism invariant level, we prove that plLQG is equivalent to standard LQG, as long…

General Relativity and Quantum Cosmology · Physics 2010-01-21 Jonathan Engle

Quantum Field Theory on Curved Spacetime (QFT on CS) is a well established theoretical framework which intuitively should be a an extremely effective description of the quantum nature of matter when propagating on a given background…

General Relativity and Quantum Cosmology · Physics 2009-11-30 Kristina Giesel , Johannes Tambornino , Thomas Thiemann

We investigate a certain distributional extension of the group of spatial diffeomorphisms in Loop Quantum Gravity. This extension, which is given by the automorphisms Aut(P) of the path groupoid P, was proposed by Velhinho and is inspired…

General Relativity and Quantum Cosmology · Physics 2009-11-18 Benjamin Bahr , Thomas Thiemann

We quantize spherically symmetric vacuum gravity without gauge fixing the diffeomorphism constraint. Through a rescaling, we make the algebra of Hamiltonian constraints Abelian and therefore the constraint algebra is a true Lie algebra.…

General Relativity and Quantum Cosmology · Physics 2013-12-18 Rodolfo Gambini , Jorge Pullin

This introductory review is addressed to beginning researchers. Some of the distinguishing features of loop quantum gravity are illustrated through loop quantum cosmology of FRW models. In particular, these examples illustrate: i) how…

General Relativity and Quantum Cosmology · Physics 2010-11-11 Abhay Ashtekar

Loop Quantum Cosmology (LQC), mainly due to Bojowald, is not the cosmological sector of Loop Quantum Gravity (LQG). Rather, LQC consists of a truncation of the phase space of classical General Relativity to spatially homogeneous situations…

General Relativity and Quantum Cosmology · Physics 2009-11-11 Johannes Brunnemann , Thomas Thiemann

An open issue in loop quantum gravity (LQG) is the introduction of a non-vanishing cosmological constant $\Lambda$. In 3d, Chern-Simons theory provides some guiding lines: $\Lambda$ appears in the quantum deformation of the gauge group. The…

General Relativity and Quantum Cosmology · Physics 2014-12-03 Maïté Dupuis , Florian Girelli

In loop quantum gravity in the connection representation, the quantum configuration space $\bar{\mathcal{A}/\mathcal{G}}$, which is a compact space, is much larger than the classical configuration space $\mathcal{A}/% \mathcal{G}$ of…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Andreas Doering , Hans F. de Groote

We describe the basic assumptions and key results of loop quantum gravity, which is a background independent approach to quantum gravity. The emphasis is on the basic physical principles and how one deduces predictions from them, at a level…

High Energy Physics - Theory · Physics 2017-08-23 Lee Smolin

The topos theory is a theory which is used for deciding a number of problems of theory of relativity, gravitation and quantum physics. In the article spherically symmetric solution of the vacuum Einstein equations in the Intuitionistic…

General Relativity and Quantum Cosmology · Physics 2007-05-23 A. K. Guts , A. A. Zvyagintsev

Understanding the quantum aspects of gravity is not only a matter of equations and experiments. Gravity is intimately connected with the structure of space and time, and understanding quantum gravity requires us to find a conceptual…

General Relativity and Quantum Cosmology · Physics 2022-11-29 Carlo Rovelli , Francesca Vidotto

I describe a possible perspective on the current state of loop quantum gravity, at the light of the developments of the last years. I point out that a theory is now available, having a well-defined background-independent kinematics and a…

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

We study the Hamiltonian formulation of the generally covariant theory defined by the Lagrangian 4-form L=e_I e_J F^{IJ}(\omega) where e^I is a tetrad field and F^{IJ} is the curvature of a Lorentz connection \omega^{IJ}. This theory can be…

General Relativity and Quantum Cosmology · Physics 2015-03-13 Lihui Liu , Merced Montesinos , Alejandro Perez

We use the mathematical framework of loop quantum gravity (LQG) to study the quantization of three dimensional (Riemannian) gravity with positive cosmological constant (Lambda>0). We show that the usual regularization techniques (successful…

General Relativity and Quantum Cosmology · Physics 2014-11-20 Alejandro Perez , Daniele Pranzetti

Loop quantum gravity is an approach to quantum gravity that starts from the Hamiltonian formulation in terms of a connection and its canonical conjugate. Quantization proceeds in the spirit of Dirac: First one defines an algebra of basic…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Jerzy Lewandowski , Andrzej Okolow , Hanno Sahlmann , Thomas Thiemann

The free quantum states of topologically massive electrodynamics and gravity in 2+1 dimensions, are explicitly found. It is shown that in both theories the states are described by infrared-regular polarization tensors containing a…

High Energy Physics - Theory · Physics 2016-09-06 G. Grignani , P. Sodano , C. A. Scrucca

We present an introduction to the canonical quantization of gravity performed in loop quantum gravity, based on lectures held at the 3rd quantum geometry and quantum gravity school in Zakopane in 2011. A special feature of this introduction…

General Relativity and Quantum Cosmology · Physics 2022-12-07 Kristina Giesel , Hanno Sahlmann

Physics in (canonical) quantum gravity needs to be manifestly diffeomorphism-invariant. Consequently, physical observables need to be formulated in terms of manifestly diffeomorphism-invariant operators, which are necessarily composite.…

High Energy Physics - Theory · Physics 2023-02-15 Axel Maas