English
Related papers

Related papers: Nonconformally Ricci-flat instantons in Conformal …

200 papers

Gravitational instantons ''Lambda-instantons'' are defined here for any given value Lambda of the cosmological constant. A multiple of the Euler characteristic appears as an upper bound for the de Sitter action and as a lower bound for a…

High Energy Physics - Theory · Physics 2009-11-11 Bernard Julia , Jerome Levie , Sebastien Ray

In this work we investigate some non-Newtonian effects in exact solutions of the Einstein equations, which describe stationary and axisymmetric configurations of self-gravitating dust. A distinctive feature of these solutions is the…

General Relativity and Quantum Cosmology · Physics 2024-12-18 Matteo Fontana , Federico Scali , Sergio Luigi Cacciatori

We analyze the asymptotic solutions of Chiral Gravity (Topologically Massive Gravity at \mu l = 1 with Brown-Henneaux boundary conditions) focusing on non-Einstein metrics. A class of such solutions admits curvature singularities in the…

High Energy Physics - Theory · Physics 2014-11-21 Geoffrey Compère , Sophie de Buyl , Stéphane Detournay

We prove that semiclassical gravity in conformally static, globally hyperbolic spacetimes with a massless, conformally coupled Klein-Gordon field is well posed, when viewed as a coupled theory for the dynamical conformal factor of the…

Mathematical Physics · Physics 2022-11-28 Benito A. Juárez-Aubry , Sujoy K. Modak

The second-order nonlinear responses of inviscid chiral fluids near local equilibrium are investigated by applying the chiral kinetic theory (CKT) incorporating side-jump effects. It is shown that the local equilibrium distribution function…

High Energy Physics - Theory · Physics 2019-04-09 Yoshimasa Hidaka , Shi Pu , Di-Lun Yang

We find exact solutions describing Ricci flows of four dimensional pp-waves nonlinearly deformed by two/three dimensional solitons. Such solutions are parametrized by five dimensional metrics with generic off-diagonal terms and connections…

High Energy Physics - Theory · Physics 2009-11-11 Sergiu I. Vacaru

The Dirichlet boundary-value problem and isoperimetric inequalities for positive definite regular solutions of the vacuum Einstein equations are studied in arbitrary dimensions for the class of metrics with boundaries admitting a U(1)…

High Energy Physics - Theory · Physics 2009-10-07 M. M. Akbar , G. W. Gibbons

We construct the explicit form of three almost complex structures that a Riemannian manifold with self-dual curvature admits and show that their Nijenhuis tensors vanish so that they are integrable. This proves that gravitational instantons…

General Relativity and Quantum Cosmology · Physics 2015-06-25 A. N. Aliev , Y. Nutku

We consider the cosmology of the Ricci-tensor-squared gravity in the Palatini variational approach. The gravitational action of standard general relativity is modified by adding a function f(R^abR_ab) to the Einstein-Hilbert action, and the…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Baojiu Li , John D. Barrow , David F. Mota

We study models of axi-dilaton gravity in space-time geometries with torsion. We discuss conformal re-scaling rules in both Riemannian and non-Riemannian formulations. We give static, spherically symmetric solutions and examine their…

General Relativity and Quantum Cosmology · Physics 2010-11-19 H. Cebeci , T. Dereli

We consider the Brans-Dicke theory in non-metricity gravity, which belongs to the family of symmetric teleparallel scalar-tensor theories. Our focus lies in exploring the implications of the conformal transformation, as we derive the…

General Relativity and Quantum Cosmology · Physics 2023-10-26 Andronikos Paliathanasis

In this manuscript, a conformally invariant theory of gravitation in the context of metric measure space is studied. The proposed action is invariant under both diffeomorphism and conformal transformations. Using the variational method, a…

General Relativity and Quantum Cosmology · Physics 2015-10-06 Nafiseh Rahmanpour , Hossein Shojaie

In this note we prove that any four-dimensional half conformally flat gradient steady Ricci soliton must be either Bryant's soliton or Ricci flat. We also classify four-dimensional half conformally flat gradient shrinking Ricci solitons…

Differential Geometry · Mathematics 2011-02-08 Xiuxiong Chen , Yuanqi Wang

We discuss the conditions under which classically conformally invariant models in four dimensions can arise out of non-conformal (Einstein) gravity. As an `existence proof' that this is indeed possible we show how to derive N=4 super Yang…

High Energy Physics - Theory · Physics 2009-10-29 Krzysztof A. Meissner , Hermann Nicolai

We present novel regular Euclidean solutions to General Relativity in presence of Maxwell and conformally coupled scalar fields. In particular, we consider metrics of the Eguchi-Hanson and Taub-NUT families to solve the field equations…

High Energy Physics - Theory · Physics 2022-06-13 José Barrientos , Adolfo Cisterna , Cristóbal Corral , Marcelo Oyarzo

Our focus is on a specific type-N space-time that exhibits closed time-like curves in general relativity theory within the framework of Ricci-inverse gravity model. The matter-energy content is solely composed of a pure radiation field, and…

General Relativity and Quantum Cosmology · Physics 2023-12-27 F. Ahmed , J. C. R. de Souza , A. F. Santos

We study the renormalizable quantum gravity formulated as a perturbed theory from conformal field theory (CFT) on the basis of conformal gravity in four dimensions. The conformal mode in the metric field is managed non-perturbatively…

High Energy Physics - Theory · Physics 2009-11-10 Ken-ji Hamada

A new two-parameter asymptotically flat (AF) toric gravitational instanton is identified as a special case of the Euclidean double Kerr-NUT solution, by imposing certain symmetry and regularity conditions on its rod structure. These…

General Relativity and Quantum Cosmology · Physics 2026-05-28 Edward Teo

In this thesis we study the momentum space approach to the solution of the CWI's of CFT's in higher dimensions. Our work's goal is to illustrate the essential steps needed to build tensor correlators starting from the scalar solutions, for…

High Energy Physics - Theory · Physics 2021-04-02 Matteo Maria Maglio

We study vertex operators in 4D conformal field theory derived from quantized gravity, whose dynamics is governed by the Wess-Zumino action by Riegert and the Weyl action. Conformal symmetry is equal to diffeomorphism symmetry in the…

High Energy Physics - Theory · Physics 2011-03-31 Ken-ji Hamada