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The recently introduced manifestly covariant canonical quantization scheme is applied to gravity. New diffeomorphism anomalies generating a multi-dimensional generalization of the Virasoro algebra arise. This does not contradict theorems…

High Energy Physics - Theory · Physics 2007-05-23 T. A. Larsson

It is widely accepted that the fundamental geometrical law of nature should follow from an action principle. The particular subset of transformations of a system's dynamical variables that maintain the form of the action principle comprises…

General Relativity and Quantum Cosmology · Physics 2015-04-24 Jürgen Struckmeier

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

A careful study of the induced transformations on spatial quantities due to 4-dimensional spacetime diffeomorphisms in the canonical formulation of general relativity is undertaken. Use of a general formalism, which indicates the role of…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Frank Antonsen , Fotini Markopoulou

Classical background independence is reflected in Lagrangian general relativity through covariance under the full diffeomorphism group. We show how this independence can be maintained in a Hamilton-Jacobi approach that does not accord…

General Relativity and Quantum Cosmology · Physics 2021-06-22 Donald Salisbury , Jürgen Renn , Kurt Sundermeyer

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

The standard geometrodynamics is transformed into a theory of conformal geometrodynamics by extending the ADM phase space for canonical general relativity to that consisting of York's mean exterior curvature time, conformal three-metric and…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Charles H. -T. Wang

Canonical quantization of spherically symmetric space-times is carried out, using real-valued densitized triads and extrinsic curvature components, with specific factor ordering choices ensuring in an anomaly free quantum constraint…

General Relativity and Quantum Cosmology · Physics 2015-06-05 Suddhasattwa Brahma

A starting point for the present work was the statement recently discussed in the literature that two Hamiltonian formulations for the theory of gravity, the one proposed by Dirac and the other by Arnowitt - Deser - Misner, may not be…

General Relativity and Quantum Cosmology · Physics 2011-03-07 T. P. Shestakova

We apply the covariant analytic mechanics with the differential forms to the Dirac field and the gravity with the Dirac field. The covariant analytic mechanics treats space and time on an equal footing regarding the differential forms as…

General Relativity and Quantum Cosmology · Physics 2016-05-25 Satoshi Nakajima

We show that representations of the group of spacetime diffeomorphism and the Dirac algebra both arise in a phase-space histories version of canonical general relativity. This is the general-relativistic analogue of the novel time structure…

General Relativity and Quantum Cosmology · Physics 2014-11-17 Ntina Savvidou

We propose a manifestly covariant canonical method of field quantization based on the classical De Donder-Weyl covariant canonical formulation of field theory. Owing to covariance, the space and time arguments of fields are treated on an…

High Energy Physics - Theory · Physics 2009-01-07 H. Nikolic

The problem of observables in classical and quantum gravity is a long-standing one. It is sometimes argued that observable quantities should be diffeomorphsm invariant, following the philosophy of Dirac. We argue that diffeomorphism…

General Relativity and Quantum Cosmology · Physics 2012-06-06 Manfred Requardt

The conventional group of four-dimensional diffeomorphisms is not realizeable as a canonical transformation group in phase space. Yet there is a larger field-dependent symmetry transformation group which does faithfully reproduce 4-D…

General Relativity and Quantum Cosmology · Physics 2009-11-10 D. C. Salisbury

We give an overview of some conceptual difficulties, sometimes called paradoxes, that have puzzled for years the physical interpetation of classical canonical gravity and, by extension, the canonical formulation of generally covariant…

General Relativity and Quantum Cosmology · Physics 2015-05-18 J. M. Pons , D. C. Salisbury , K. A. Sundermeyer

This is a review of the chrono-geometrical structure of special and general relativity with a special emphasis on the role of non-inertial frames and of the conventions for the synchronization of distant clocks. ADM canonical metric and…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Luca Lusanna

We combine the "evolving constants" approach to the construction of observables in canonical quantum gravity with the Page--Wootters formulation of quantum mechanics with a relational time for generally covariant systems. This overcomes the…

General Relativity and Quantum Cosmology · Physics 2009-11-06 Rodolfo Gambini , Rafael Porto , Sebastian Torterolo , Jorge Pullin

The construction of Dirac observables, that is gauge invariant objects, in General Relativity is technically more complicated than in other gauge theories such as the standard model due to its more complicated gauge group which is closely…

General Relativity and Quantum Cosmology · Physics 2014-11-20 K. Giesel , J. Tambornino , T. Thiemann

The Hamiltonian formulation of general relativity (GR) is considered in finite space-time and a specific frame of reference given by the diffeo-invariant components of the Fock simplex in terms of the Dirac -- ADM variables. The evolution…

Astrophysics · Physics 2009-11-13 B. M. Barbashov , V. N. Pervushin , A. F. Zakharov , V. A. Zinchuk

Peter Bergmann and his students embarked in 1949 on a mainly canonical quantization program whose aim was to take into account the underlying four-dimensional diffeomorphism symmetry in the transition from a Lagrangian to a Hamiltonian…

History and Philosophy of Physics · Physics 2020-12-25 Donald Salisbury