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A new semi-supervised machine learning package is introduced which successfully solves the Euclidean vacuum Einstein equations with a cosmological constant, without any symmetry assumptions. The model architecture contains subnetworks for…

High Energy Physics - Theory · Physics 2025-10-21 Edward Hirst , Tancredi Schettini Gherardini , Alexander G. Stapleton

We study the existence of conformal metrics on non-compact Riemannian manifolds with non-compact boundary, which are complete as metric spaces and have negative constant scalar curvature in the interior and negative constant mean curvature…

Differential Geometry · Mathematics 2022-09-02 Juan Alcon Apaza , Sergio Almaraz

In this paper, we study a new class of Finsler metrics, F=\alpha\phi(b^2,s), s:=\beta/\alpha, defined by a Riemannian metric \alpha and 1-form \beta. It is called general (\alpha, \beta) metric. In this paper, we assume \phi be coefficient…

Differential Geometry · Mathematics 2017-06-28 A. Ala , A. Behzadi , M. Rafiei-Rad

The aim of the paper is to extend the notion of $\alpha$-geometry in the classical and in the noncommutative case by introducing a more general class of pull-back metrics and to give concrete formulas for the scalar curvature of these…

Mathematical Physics · Physics 2008-01-23 Attila Andai

The general solution of Einstein's gravity equation in $D$ dimensions for an anisotropic and spherically symmetric matter distribution is calculated in a bulk with position dependent cosmological constant. Results for $n$ concentric…

General Relativity and Quantum Cosmology · Physics 2013-03-01 I. C. Jardim , R. R. Landim , G. Alencar , R. N. Costa Filho

We show a closed Bach-flat Riemannian manifold with a fixed positive constant scalar curvature has to be locally spherical if its Weyl and traceless Ricci tensors are small in the sense of either $L^\infty$ or $L^{\frac{n}{2}}$-norm.…

Differential Geometry · Mathematics 2017-04-24 Yi Fang , Wei Yuan

We study metric spaces homeomorphic to the 2-sphere, and find conditions under which they are quasisymmetrically homeomorphic to the standard 2-sphere. As an application of our main theorem we show that an Ahlfors 2-regular, linearly…

Metric Geometry · Mathematics 2015-06-26 Mario Bonk , Bruce Kleiner

Supersymmetric domain-wall spacetimes that lift to Ricci-flat solutions of M-theory admit generalized Heisenberg (2-step nilpotent) isometry groups. These metrics may be obtained from known cohomogeneity one metrics of special holonomy by…

High Energy Physics - Theory · Physics 2009-10-07 G. W. Gibbons , H. Lu , C. N. Pope , K. S. Stelle

Canonical metrics and conformal invariants are presented for closed oriented even-dimensional manifolds with non-degenerate conformal structures and in particular for compact Riemann surfaces.

Differential Geometry · Mathematics 2011-06-21 Dmitri Scheglov

We consider a generalization of Riemannian geometry that naturally arises in the framework of control theory. Let $X$ and $Y$ be two smooth vector fields on a two-dimensional manifold $M$. If $X$ and $Y$ are everywhere linearly independent,…

Optimization and Control · Mathematics 2007-05-23 Andrei A. Agrachev , Ugo Boscain , Mario Sigalotti

We consider the problem of preserving weighted Riemannian metrics of positive Bakry-\'Emery Ricci curvature along surgery. We establish two theorems of this type: One for connected sums, and one for surgeries along higher-dimensional…

Differential Geometry · Mathematics 2024-11-27 Philipp Reiser , Francesca Tripaldi

We consider the problem of finding a metric in a given conformal class with prescribed non-positive scalar curvature and non-positive boundary mean curvature on an asymptotically Euclidean manifold with inner boundary. We obtain a necessary…

Analysis of PDEs · Mathematics 2023-08-22 Vladmir Sicca , Gantumur Tsogtgerel

Let $M=G/K$ be a generalized flag manifold, that is the adjoint orbit of a compact semisimple Lie group $G$. We use the variational approach to find invariant Einstein metrics for all flag manifolds with two isotropy summands. We also…

Differential Geometry · Mathematics 2019-11-25 Andreas Arvanitoyeorgos , Ioannis Chrysikos

An almost Einstein manifold satisfies equations which are a slight weakening of the Einstein equations; Einstein metrics, Poincare-Einstein metrics, and compactifications of certain Ricci-flat asymptotically locally Euclidean structures are…

Differential Geometry · Mathematics 2008-03-26 A. Rod Gover

We give a general procedure for gluing together possibly noncompact manifolds of constant scalar curvature which satisfy an extra nondegeneracy hypothesis. Our aim is to provide a simple paradigm for making `analytic' connected sums. In…

dg-ga · Mathematics 2008-02-03 Rafe Mazzeo , Daniel Pollack , Karen Uhlenbeck

We derive new, sharp lower bounds for certain curvature functionals on the space of Riemannian metrics of a smooth compact 4-manifold with a non-trivial Seiberg-Witten invariant. These allow one, for example, to exactly compute the infimum…

Differential Geometry · Mathematics 2009-10-31 Claude LeBrun

In this paper, as an application of the inverse problem of calculus of variations, we investigate two compatibility conditions on the spherically symmetric Finsler metrics. By making use of these conditions, we focus our attention on the…

Differential Geometry · Mathematics 2021-10-15 S. G. Elgendi

This paper considers the existence of conformally compact Einstein metrics on 4-manifolds. A reasonably complete understanding is obtained for the existence of such metrics with prescribed conformal infinity, when the conformal infinity is…

Differential Geometry · Mathematics 2008-03-18 Michael T. Anderson

We obtain the most general spherically symmetric M2-branes and type IIB strings, with \R^{1,2}\times SO(8) and \R^{1,1}\times SO(8) isometries respectively. We find that there are twelve different classes of M2-branes, and we study their…

High Energy Physics - Theory · Physics 2009-09-19 Zhao-Long Wang , H. Lu

Motivated by the work of Li and Mantoulidis, we study singular metrics which are uniformly Euclidean $(L^\infty)$ on a compact manifold $M^n$ ($n\ge 3$) with negative Yamabe invariant $\sigma(M)$. It is well-known that if $g$ is a smooth…

Differential Geometry · Mathematics 2021-07-20 Man-Chuen Cheng , Man-Chun Lee , Luen-Fai Tam