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Related papers: Space-time Averages of Classical Physical Fields

200 papers

This is intended as an analysis of the global properties of static and stationary spacetimes with complete (timelike) Killing field, with particular attention to quotients by group actions. This is presented in terms of algebraic structures…

General Relativity and Quantum Cosmology · Physics 2015-06-24 Steven G. Harris

We present a new approach for averaging in general relativity and cosmology. After a short review of the theory originally taken from the equivalence problem, we consider two ways how to deal with averaging based on Cartan scalars. We apply…

General Relativity and Quantum Cosmology · Physics 2014-05-23 Petr Kaspar , Otakar Svitek

An averaging operator on an associative algebra $A$ is an algebraic abstraction of the time average operator on the space of real-valued functions defined in time-space. In this paper, we consider relative averaging operators on a bimodule…

Rings and Algebras · Mathematics 2023-04-03 Apurba Das

A general relativistic description of a disk rotating at constant angular velocity is given. It is argued that conceptually this direct approach poses fewer problems than the special relativistic one. For observers on the disk, the geometry…

Popular Physics · Physics 2015-05-30 Klaus Kassner

The conventional phase space of classical physics treats space and time differently, and this difference carries over to field theories and quantum mechanics (QM). In this paper, the phase space is enhanced through two main extensions.…

Quantum Physics · Physics 2024-05-15 N. L. Diaz , J. M. Matera , R. Rossignoli

The covariance of loop quantum gravity studies of spherically symmetric space-times has recently been questioned. This is a reasonable worry, given that they are formulated in terms of slicing-dependent variables. We show explicitly that…

General Relativity and Quantum Cosmology · Physics 2022-02-21 Rodolfo Gambini , Javier Olmedo , Jorge Pullin

Field equations with general covariance are interpreted as equations for a target space describing physical space time co-ordinates, in terms of an underlying base space with conformal invariance. These equations admit an infinite number of…

High Energy Physics - Theory · Physics 2008-11-26 D. B. Fairlie , R. Zhdanov

Quantum statistical mechanics is formulated as an integral over classical phase space. Some details of the commutation function for averages are discussed, as is the factorization of the symmetrization function used for the grand potential…

Quantum Physics · Physics 2018-11-05 Phil Attard

We formulate axisymmetric general relativity in terms of real Ashtekar--Barbero variables. We study the constraints and equations of motion and show how the Kerr, Schwarzschild and Minkowski solutions arise. We also discuss boundary…

General Relativity and Quantum Cosmology · Physics 2019-06-03 Rodolfo Gambini , Esteban Mato , Javier Olmedo , Jorge Pullin

In a recent paper (arXiv:1412.6000) a general mechanism for emergence of cosmological space-time geometry from a quantum gravity setting was devised and departure from standard dispersion relations for elementary particle were predicted. We…

General Relativity and Quantum Cosmology · Physics 2015-12-16 Ricardo Gallego Torromé , Marco Letizia , Stefano Liberati

The approximations of classical mechanics resulting from quantum mechanics are richer than a correspondence of classical dynamical variables with self-adjoint Hilbert space operators. Assertion that classical dynamic variables correspond to…

Quantum Physics · Physics 2014-09-08 Glenn Eric Johnson

We present two new covariant and general prescriptions for averaging scalar observables on spatial regions typical of the observed sources and intersecting the past light-cone of a given observer. One of these prescriptions is adapted to…

General Relativity and Quantum Cosmology · Physics 2020-02-17 Giuseppe Fanizza , Maurizio Gasperini , Giovanni Marozzi , Gabriele Veneziano

An algebraic formulation of general relativity is proposed. The formulation is applicable to quantum gravity and noncommutative space. To investigate quantum gravity we develop the canonical formalism of operator geometry, after…

High Energy Physics - Theory · Physics 2007-05-23 Masaru Siino

We informally review the construction of spacetime geometries with multifractal and, more generally, multiscale properties. Based on fractional calculus, these continuous spacetimes have their dimension changing with the scale; they display…

High Energy Physics - Theory · Physics 2012-10-10 Gianluca Calcagni

We develop the first steps towards an analysis of geometry on the quantum spacetime proposed in [1]. The homogeneous elements of the universal differential algebra are naturally identified with operators living in tensor powers of Quantum…

High Energy Physics - Theory · Physics 2015-03-17 Dorothea Bahns , Sergio Doplicher , Klaus Fredenhagen , Gherardo Piacitelli

We investigate effective equations governing the volume expansion of spatially averaged portions of inhomogeneous cosmologies in spacetimes filled with an arbitrary fluid. This work is a follow-up to previous studies focused on irrotational…

General Relativity and Quantum Cosmology · Physics 2020-03-16 Thomas Buchert , Pierre Mourier , Xavier Roy

We present a geometric proof of the averaging theorem for perturbed dynamical systems on a Riemannian manifold, in the case where the flow of the unperturbed vector field is periodic and the $\mathbb{S}^{1}$-action associated to this vector…

Differential Geometry · Mathematics 2015-12-17 Misael Avendaño Camacho , Guillermo Dávila Rascón

Time-translation symmetry strongly constrains physical dynamics, yet systematic characterization for continuous-variable systems lags behind its discrete-variable counterpart. We close this gap by providing a rigorous classification of…

I provide an alternative characterization of a "standard of rotation" in the context of classical spacetime structure that does not refer to any covariant derivative operator.

History and Philosophy of Physics · Physics 2017-07-11 James Owen Weatherall

This paper is a contribution to the development of a framework, to be used in the context of semiclassical canonical quantum gravity, in which to frame questions about the correspondence between discrete spacetime structures at "quantum…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Luca Bombelli , Alejandro Corichi , Oliver Winkler