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We present a new reformulation of the canonical quantum geometrodynamics, which allows to overcome the fundamental problem of the frozen formalism and, therefore, to construct an appropriate Hilbert space associate to the solution of the…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Simone Mercuri , Giovanni Montani

General Relativity is an extremely successful theory, at least for weak gravitational fields, however, it breaks down at very high energies, such as in correspondence of the initial singularity. Quantum Gravity is expected to provide more…

General Relativity and Quantum Cosmology · Physics 2023-04-20 Ana Rita Ribeiro , Daniele Vernieri , Francisco S. N. Lobo

Development of quantum gravity theories rarely takes inputs from experimental physics. In this letter, we take a small step towards correcting this by establishing a paradigm for incorporating putative quantum corrections, arising from…

High Energy Physics - Theory · Physics 2018-01-30 Suddhasattwa Brahma , Michele Ronco

A consistent implementation of quantum gravity is expected to change the familiar notions of space, time and the propagation of matter in drastic ways. This will have consequences on very small scales, but also gives rise to correction…

General Relativity and Quantum Cosmology · Physics 2009-08-26 Martin Bojowald , Golam Mortuza Hossain , Mikhail Kagan , S. Shankaranarayanan

Quantum corrections of certain types and relevant in certain regimes can be summarised in terms of an effective action calculable, in principle, from the underlying theory. The demands of symmetries, local form of terms and dimensional…

General Relativity and Quantum Cosmology · Physics 2009-04-17 Ghanashyam Date , Sandipan Sengupta

The cosmological tensor perturbation equation with generalized holonomy corrections is derived in the framework of effective loop quantum gravity. This results in a generalized dispersion relation for gravitational waves, encompassing…

General Relativity and Quantum Cosmology · Physics 2024-08-13 Shulan Li , Jian-Pin Wu

We describe a deformation of the observable algebra of quantum gravity in which the loop algebra is extended to framed loops. This allows an alternative nonperturbative quantization which is suitable for describing a phase of quantum…

General Relativity and Quantum Cosmology · Physics 2009-09-25 Seth Major , Lee Smolin

It is possible to implement a certain form of modified gravity inspired by loop quantization through non-bijective canonical transformations. The canonical nature might suggest that such modifications are guaranteed to preserve general…

General Relativity and Quantum Cosmology · Physics 2021-07-07 Martin Bojowald

A model is proposed to demonstrate that classical general relativity can emerge from loop quantum gravity, in a relational description of gravitational field in terms of the coordinates given by matter. Local Dirac observables and coherent…

General Relativity and Quantum Cosmology · Physics 2015-06-03 Chun-Yen Lin

A recent paper promises new constructions that may make it possible to achieve covariance in spherically symmetric models of loop quantum gravity. This claim is contrary to the discovery of several stubborn obstacles to covariance uncovered…

General Relativity and Quantum Cosmology · Physics 2023-01-05 Martin Bojowald

The canonical approach to quantum gravity has been put on a firm mathematical foundation in the recent decades. Even the quantum dynamics can be rigorously defined, however, due to the tremendously non-polynomial character of the…

General Relativity and Quantum Cosmology · Physics 2020-03-31 Thomas Thiemann

Various candidates of quantum gravity such as string theory, loop quantum gravity and black hole physics all predict the existence of a minimum observable length which modifies the Heisenberg uncertainty principle to so-called Generalized…

High Energy Physics - Theory · Physics 2015-03-19 Pouria Pedram

A model is proposed to demonstrate that classical general relativity can emerge from loop quantum gravity, in a relational description of gravitational field in terms of coordinates given by matter. Local Dirac observables and coherent…

General Relativity and Quantum Cosmology · Physics 2011-03-29 Chun-Yen Lin

The general uncertainty principle applied to gravity can be implemented as a set of modified Poisson brackets in the canonical formalism. As such, the theory is not canonical and the resulting equations of motion do not lead to a covariant…

General Relativity and Quantum Cosmology · Physics 2026-05-08 Douglas M. Gingrich

This article lays out a complete framework for an effective theory of cosmological perturbations with corrections from canonical quantum gravity. Since several examples exist for quantum-gravity effects that change the structure of…

General Relativity and Quantum Cosmology · Physics 2015-05-27 Aurelien Barrau , Martin Bojowald , Gianluca Calcagni , Julien Grain , Mikhail Kagan

We study an algebraic deformation problem which captures the data of the general deformation problem for a quantum vertex algebra. We derive a system of coupled equations which is the counterpart of the Maurer-Cartan equation on the usual…

High Energy Physics - Theory · Physics 2007-05-23 Harald Grosse , Karl-Georg Schlesinger

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

We investigate quantum stability of the generalised Proca theories in curved spacetime treating gravity as a dynamical field. To compute the quantum gravitational corrections we evaluate divergent part of the effective action at one loop…

High Energy Physics - Theory · Physics 2022-02-09 Sukanta Panda , Abbas Tinwala , Archit Vidyarthi

The longstanding issue of general covariance in effective models of quantum gravity is addressed, which arises when canonical quantum gravity leads to a semiclassical model described by an effective Hamiltonian constraint. In the context of…

General Relativity and Quantum Cosmology · Physics 2026-03-05 Cong Zhang , Jerzy Lewandowski , Yongge Ma , Jinsong Yang

The basic features of the complex canonical formulation of general relativity and the recent developments in the quantum gravity program based on it are reviewed. The exposition is intended to be complementary to the review articles…

General Relativity and Quantum Cosmology · Physics 2010-11-01 Hideo Kodama