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Related papers: On weakly Einstein K\"ahler surfaces

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The existence of \emph{weak conical K\"ahler-Einstein} metrics along smooth hypersurfaces with angle between $0$ and $2\pi$ is obtained by studying a smooth continuity method and a \emph{local Moser's iteration} technique. In the case of…

Differential Geometry · Mathematics 2013-08-21 Chengjian Yao

A 3-dimensional Riemannian manifold equipped with a tensor structure of type $(1,1)$, whose fourth power is the identity, is considered. This structure acts as an isometry with respect to the metric. A Riemannian almost product manifold…

Differential Geometry · Mathematics 2025-06-06 Iva Dokuzova

In this paper, we investigate the geometry of Einstein-type equation on a Riemannian manifold, unifying various particular geometric structures recently studied in the literature, such as critical point equation and vacuum static equation.…

Differential Geometry · Mathematics 2022-03-31 Gabjin Yun , Seungsu Hwang

In this paper we discuss when a quasi-conformally flat weakly Ricci symmetric manifold (of dimension greater than 3) becomes a manifold of hyper quasi-constant curvature, a quasi-Einstein manifold and a manifold of quasi-constant curvature.…

General Mathematics · Mathematics 2021-06-28 Payel Karmakar , Arindam Bhattacharyya

We obtain a class of locally symmetric Kaehler Einstein structures on the cotangent bundle of a Riemannian manifold of negative sectional curvature. Similar results are obtained in the case of a Riemannian manifold of positive sectional…

Differential Geometry · Mathematics 2007-05-23 D. D. Porosniuc

Any oriented $4$-dimensional Einstein metric with semi-definite sectional curvature satisfies the pointwise inequality \[ \frac{|s|}{\sqrt{6}}\geq|W^+|+|W^-|, \] where $s$, $W^+$ and $W^-$ are respectively the scalar curvature, the…

Differential Geometry · Mathematics 2025-03-28 Luca F. Di Cerbo

We study metric structures on a smooth manifold (introduced in our recent works and called a weak contact metric structure and a weak K-structure) which generalize the metric contact and K-contact structures, and allow a new look at the…

Differential Geometry · Mathematics 2023-04-04 Vladimir Rovenski

We introduce a new kind of Riemannian manifold that includes weakly-, pseudo- and pseudo projective- Ricci symmetric manifolds. The manifold is defined through a generalization of the so called Z tensor; it is named "weakly Z symmetric" and…

Differential Geometry · Mathematics 2012-03-23 Carlo A. Mantica , Luca G. Molinari

The K\"ahler cone of a compact manifold carries a natural Riemannian metric, given by the intersection product of its cohomology ring. We write down the curvature tensor of this metric by embedding the K\"ahler cone in the space of…

Algebraic Geometry · Mathematics 2012-11-30 Gunnar Þór Magnússon

In this article we study almost contact manifolds admitting weakly Einstein metrics. We first prove that if a (2n+1)-dimensional Sasakian manifold admits a weakly Einstein metric then its scalar curvature $s$ satisfies $-6\leqslant s…

Differential Geometry · Mathematics 2019-09-04 Xiaomin Chen

This work is devoted to the study of Einstein equations with a special shape of the energy-momentum tensor. Our results continue Stepanov's classification of Riemannian manifolds according to special properties of the energy-momentum tensor…

Differential Geometry · Mathematics 2010-03-24 I. Hinterleitner , V. Kiosak

In this paper, we study the weakly weighted Einstein-Finsler metrics. First, we show that weakly weighted Einstein-Kropina metrics must be of isotropic S-curvature with respect to the Busemann-Hausdorff volume form under a certain condition…

Differential Geometry · Mathematics 2022-05-30 Xinyue Cheng , Hong Cheng , Pengsheng Wu

We study closed $n$-dimensional manifolds of which the metrics are critical for quadratic curvature functionals involving the Ricci curvature, the scalar curvature and the Riemannian curvature tensor on the space of Riemannian metrics with…

Differential Geometry · Mathematics 2017-07-18 Guangyue Huang

On four-dimensional closed manifolds we introduce a class of canonical Riemannian metrics, that we call weak harmonic Weyl metrics, defined as critical points in the conformal class of a quadratic functional involving the norm of the…

Differential Geometry · Mathematics 2018-10-17 Giovanni Catino , Paolo Mastrolia , Dario D. Monticelli , Fabio Punzo

We construct Einstein metrics of non-positive scalar curvature on certain solid torus bundles over a Fano Kahler-Einstein manifold. We show, among other things, that the negative Einstein metrics are conformally compact, and the Ricci-flat…

Differential Geometry · Mathematics 2011-03-07 Dezhong Chen

We show that every quaternion-K\"ahler manifold of negative scalar curvature is stable as an Einstein manifold and therefore scalar curvature rigid. In particular, this implies that every irreducible nonpositive Einstein manifold of special…

Differential Geometry · Mathematics 2024-12-19 Klaus Kroencke , Uwe Semmelmann

An Einstein manifold is called scalar curvature rigid if there are no compactly supported volume-preserving deformation of the metric which increase the scalar curvature. We give various characterizations of scalar curvature rigidity for…

Differential Geometry · Mathematics 2022-12-21 Mattias Dahl , Klaus Kroencke

Seiberg-Witten theory leads to a delicate interplay between Riemannian geometry and smooth topology in dimension four. In particular, the scalar curvature of any metric must satisfy certain non-trivial estimates if the manifold in question…

Differential Geometry · Mathematics 2016-09-07 Claude LeBrun

We obtain a class of Kaehler Einstein structures on the nonzero cotangent bundle of a Riemannian manifold of positive constant sectional curvature. The obtained class of Kaehler Einstein structure depends on one essential parameter, cannot…

Differential Geometry · Mathematics 2007-05-23 Dumitru Daniel Porosniuc

Using Seiberg-Witten theory, it is shown that any Kaehler metric of constant negative scalar curvature on a compact 4-manifold M minimizes the L^2-norm of scalar curvature among Riemannian metrics compatible with a fixed decomposition…

dg-ga · Mathematics 2008-02-03 Claude LeBrun