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Related papers: Loop Quantum Gravity Phenomenology: Linking Loops …

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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

Small violations of spacetime symmetries have recently been identified as promising Planck-scale signals. This talk reviews how such violations can arise in various approaches to quantum gravity, how the emergent low-energy effects can be…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Ralf Lehnert

Loop quantum gravity is a mature theory. To proceed to explicit calculations in cosmology, it is necessary to make assumptions and simplifications based on the symmetries of the cosmological setting. Symmetry reduction is especially…

General Relativity and Quantum Cosmology · Physics 2016-08-03 Aurélien Barrau , Boris Bolliet

We review the main theoretical motivations and observational constraints on Planck scale suppressed violations of Lorentz invariance. After introducing the problems related to the phenomenological study of quantum gravitational effects, we…

High Energy Astrophysical Phenomena · Physics 2009-12-15 Stefano Liberati , Luca Maccione

We set up a covariant renormalisation group equation on a foliated spacetime which preserves background diffeomorphism symmetry. As a first application of the new formalism, we study the effect of quantum fluctuations in Lorentz symmetry…

High Energy Physics - Theory · Physics 2019-03-27 Benjamin Knorr

Quantum General Relativity (QGR), sometimes called Loop Quantum Gravity, has matured over the past fifteen years to a mathematically rigorous candidate quantum field theory of the gravitational field. The features that distinguish it from…

General Relativity and Quantum Cosmology · Physics 2015-06-25 Thomas Thiemann

It is well known that a fundamental theorem of Quantum Field Theory (QFT) set in at spacetime ensures the CPT invariance of the theory. This symmetry is strictly connected to the Lorentz covariance, and consequently to the fundamental…

High Energy Physics - Phenomenology · Physics 2021-10-19 Vito Antonelli , Lino Miramonti , Marco Danilo Claudio Torri

Phenomenological approaches to quantum gravity try to infer model-independent laws by analyzing thought experiments and combining both quantum, relativistic, and gravitational ingredients. We first review these ingredients -three basic…

General Relativity and Quantum Cosmology · Physics 2013-08-21 Jean-Philippe Bruneton

The construction of effective Hamiltonians arising from Loop Quantum Gravity and incorporating Planck scale corrections to the dynamics of photons and spin 1/2 particles is summarized. The imposition of strict bounds upon some parameters of…

High Energy Physics - Phenomenology · Physics 2009-11-10 Luis F. Urrutia

An heuristic semiclassical procedure that incorporates quantum gravity induced corrections in the description of photons and spin 1/2 fermions is reviewed. Such modifications are calculated in the framework of loop quantum gravity and they…

General Relativity and Quantum Cosmology · Physics 2009-11-07 Luis Urrutia

New phenomenological models of Quantum Gravity have suggested that a Lorentz-Invariant discrete spacetime structure may become manifest through a nonstandard coupling of matter fields and spacetime curvature. On the other hand, there is…

General Relativity and Quantum Cosmology · Physics 2013-02-13 Mario A. Acero , Yuri Bonder

The topic of Lorentz invariance violation is a fundamental question in physics that has taken on particular interest in theoretical explorations of quantum gravity scenarios. I discuss various gamma-ray observations that give limits on…

High Energy Physics - Phenomenology · Physics 2010-04-08 Floyd W. Stecker

I give a brief overview of some Quantum-Gravity-Phenomenology research lines, focusing on studies of cosmic rays and gamma-ray bursts that concern the fate of Lorentz symmetry in quantum spacetime. I also stress that the most valuable…

General Relativity and Quantum Cosmology · Physics 2016-11-09 Giovanni Amelino-Camelia

Loop quantum gravity and cosmology are reviewed with an emphasis on evaluating the dynamics, rather than constructing it. The three crucial parts of such an analysis are (i) deriving effective equations, (ii) controlling the theory's…

General Relativity and Quantum Cosmology · Physics 2011-01-31 Martin Bojowald

Fundamental quantum gravity theories are known to be notoriously difficult to extract viable testable predictions out of. In this paper, we aim to incorporate putative quantum corrections coming from loop quantum gravity in deriving…

General Relativity and Quantum Cosmology · Physics 2017-02-15 Suddhasattwa Brahma , Michele Ronco , Giovanni Amelino-Camelia , Antonino Marciano

We discuss the applicability of the argument of Collins, P\'erez, Sudarsky, Urrutia and Vucetich to loop quantum gravity. This argument suggests that Lorentz violations, even ones that only manifest themselves at energies close to the…

General Relativity and Quantum Cosmology · Physics 2012-02-13 Rodolfo Gambini , Saeed Rastgoo , Jorge Pullin

Polymer quantum mechanics has been studied as a simplified picture that reflects some of the key properties of Loop Quantum Gravity; however, while the fate of relativistic symmetries in Loop Quantum Gravity is still not established, it is…

General Relativity and Quantum Cosmology · Physics 2017-12-06 Giovanni Amelino-Camelia , Michele Arzano , Malú Maira Da Silva , Daniel H. Orozco-Borunda

Loop quantum cosmology is a symmetry reduced quantization of cosmological spacetimes based on loop quantum gravity. While it has been successful in resolution of various cosmological singularities and connecting Planck scale physics to…

General Relativity and Quantum Cosmology · Physics 2019-12-25 Klaus Liegener , Parampreet Singh

This article concerns the fate of local Lorentz invariance in quantum gravity, particularly for approaches in which a discrete structure replaces continuum spacetime. Some features of standard quantum mechanics, presented in a…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Joe Henson

A fully consistent linear perturbation theory for cosmology is derived in the presence of quantum corrections as they are suggested by properties of inverse volume operators in loop quantum gravity. The underlying constraints present a…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Martin Bojowald , Golam Mortuza Hossain , Mikhail Kagan , S. Shankaranarayanan