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Related papers: Non-Local Properties in Euclidean Quantum Gravity

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We study the matter one-loop quantum corrections to the gravitational sector in a gravity theory coupled with a nonlocal scalar field. We find that non-renormalizable divergences disappear when the propagator of the scalar field approaches…

High Energy Physics - Theory · Physics 2011-06-21 Takayuki Hirayama

A key problem in the attempt to quantize the gravitational field is the choice of boundary conditions. These are mixed, in that spatial and normal components of metric perturbations obey different sets of boundary conditions. In the…

High Energy Physics - Theory · Physics 2007-05-23 Ivan G. Avramidi , Giampiero Esposito

A general method exists for studying Abelian and non-Abelian gauge theories, as well as Euclidean quantum gravity, at one-loop level on manifolds with boundary. In the latter case, boundary conditions on metric perturbations h can be chosen…

High Energy Physics - Theory · Physics 2007-05-23 Giampiero Esposito , Guglielmo Fucci , Alexander Yu. Kamenshchik , Klaus Kirsten

In the eighties, Schroder studied a quantum mechanical model where the stationary states of Schrodinger's equation obey nonlocal boundary conditions on a circle in the plane. For such a problem, we perform a detailed one-loop calculation…

High Energy Physics - Theory · Physics 2019-03-27 Giampiero Esposito , Elisabetta Di Grezia

We review what is known about boundary conditions in General Relativity on a spacetime of Euclidean signature. The obvious Dirichlet boundary condition, in which one specifies the boundary geometry, is actually not elliptic and in general…

High Energy Physics - Theory · Physics 2023-07-18 Edward Witten

A general method is known to exist for studying Abelian and non-Abelian gauge theories, as well as Euclidean quantum gravity, at one-loop level on manifolds with boundary. In the latter case, boundary conditions on metric perturbations h…

High Energy Physics - Theory · Physics 2009-11-10 Giampiero Esposito , Guglielmo Fucci , Alexander Yu. Kamenshchik , Klaus Kirsten

When quantum fields are studied on manifolds with boundary, the corresponding one-loop quantum theory for bosonic gauge fields with linear covariant gauges needs the assignment of suitable boundary conditions for elliptic differential…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Giampiero Esposito

This paper describes recent progress in the analysis of relativistic gauge conditions for Euclidean Maxwell theory in the presence of boundaries. The corresponding quantum amplitudes are studied by using Faddeev-Popov formalism and…

General Relativity and Quantum Cosmology · Physics 2011-04-20 Giampiero Esposito

We study the problem of gauge-invariance and gauge-dependence in one-loop quantum cosmology. We formulate some requirements which should be satisfied by boundary conditions in order to give gauge-independent path integral. The case of QED…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Dmitri V. Vasilevich

In the example of $R^2+T^2$ gravity on the unit two dimensional disk we demonstrate that in the presence of an independent spin connection it is possible to define local gauge invariant boundary conditions even on boundaries which are not…

High Energy Physics - Theory · Physics 2015-06-26 Dmitri V. Vassilevich

When quantum fields are studied on manifolds with boundary, the corresponding one-loop quantum theory for bosonic gauge fields with linear covariant gauges needs the assignment of suitable boundary conditions for elliptic differential…

High Energy Physics - Theory · Physics 2017-08-23 Giampiero Esposito

We study perturbative noncommutative quantum gravity by expanding the gravitational field about a fixed classical background. A calculation of the one loop gravitational self-energy graph reveals that only the non-planar graviton loops are…

High Energy Physics - Theory · Physics 2009-10-31 J. W. Moffat

The Euclidean path integral for gravity is enriched by the addition of boundaries, which provide useful probes of thermodynamic properties. Common boundary conditions include Dirichlet conditions on the boundary induced metric;…

High Energy Physics - Theory · Physics 2025-09-22 Patrick Draper , Manthos Karydas , Hao Zhang

We revisit the subject of one-loop determinants in AdS$_3$ gravity via the quasinormal mode method. Our goal is to evaluate a one-loop determinant with chiral boundary conditions for the metric field; chirality is achieved by imposing…

High Energy Physics - Theory · Physics 2017-11-22 Alejandra Castro , Cynthia Keeler , Phillip Szepietowski

We perform a general computation of the off-shell one-loop divergences in Einstein gravity, in a two-parameter family of path integral measures, corresponding to different ways of parametrizing the graviton field, and a two-parameter family…

High Energy Physics - Theory · Physics 2016-07-20 N. Ohta , R. Percacci , A. D. Pereira

The fundamental laws of physics can be derived from the requirement of invariance under suitable classes of transformations on the one hand, and from the need for a well-posed mathematical theory on the other hand. As a part of this…

High Energy Physics - Theory · Physics 2016-12-28 Giampiero Esposito

Degenerate geometrical configurations in quantum gravity are important to understand if the fate of classical singularities is to be revealed. However, not all degenerate configurations arise on an equal footing, and one must take into…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Martin Bojowald

We study the properties of a non-abelian gauge theory subjected to a gauge invariant constraint given by the classical equations of motion. The constraint is not imposed by hand, but appears naturally when we study a particular type of…

High Energy Physics - Theory · Physics 2016-08-16 Jorge Alfaro , Pedro Labraña

This paper studies the 1-loop approximation for a massless spin-1/2 field on a flat four-dimensional Euclidean background bounded by two concentric 3-spheres, when non-local boundary conditions of the spectral type are imposed. The use of…

High Energy Physics - Theory · Physics 2009-10-30 Giampiero Esposito

The discrepancy between the results of covariant and non-covariant one-loop calculations for higher-spin fields in quantum cosmology is analyzed. A detailed mode-by-mode study of perturbative quantum gravity about a flat Euclidean…

General Relativity and Quantum Cosmology · Physics 2009-10-28 Giampiero Esposito , Alexander Yu. Kamenshchik , Igor V. Mishakov , Giuseppe Pollifrone