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Related papers: Towards conformally flat isothermic metrics

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Certain semi-Riemannian metrics can be decomposed into a Riemannian part and an isochronal part. The properties of such metrics are particularly easy to visualize in a coordinate-free way, using isometric embedding. We present such an…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Earnest Harrison

We determine the local structure of all pseudo-Riemannian manifolds $(M,g)$ in dimensions $n\ge4$ whose Weyl conformal tensor $W$ is parallel and has rank 1 when treated as an operator acting on exterior 2-forms at each point. If one fixes…

Differential Geometry · Mathematics 2010-11-30 Andrzej Derdzinski , Witold Roter

We derive some necessary conditions on a Riemannian metric $(M, g)$ in four dimensions for it to be locally conformal to K\"ahler. If the conformal curvature is non anti--self--dual, the self--dual Weyl spinor must be of algebraic type $D$…

Differential Geometry · Mathematics 2015-05-13 Maciej Dunajski , Paul Tod

In this paper, we consider the problem of existence and multiplicity of conformal metrics on a riemannian compact $4-$dimensional manifold $(M^4,g_0)$ with positive scalar curvature. We prove new exitence criterium which provides existence…

Differential Geometry · Mathematics 2009-06-10 Hichem Chtioui , Mohameden Ould Ahmedou

Let $R$ be a constant. Let $\mathcal{M}^R_\gamma$ be the space of smooth metrics $g$ on a given compact manifold $\Omega^n$ ($n\ge 3$) with smooth boundary $\Sigma $ such that $g$ has constant scalar curvature $R$ and $g|_{\Sigma}$ is a…

Differential Geometry · Mathematics 2009-01-06 Pengzi Miao , Luen-Fai Tam

We found a class of triangulated surfaces in Euclidean space which have similar properties as isothermic surfaces in Differential Geometry. We call a surface isothermic if it admits an infinitesimal isometric deformation preserving the mean…

Differential Geometry · Mathematics 2016-02-16 Wai Yeung Lam , Ulrich Pinkall

We propose a unified approach to the study of isometries on algebras of vector-valued Lipschitz maps and those of continuously differentiable maps by means of the notion of admissible quadruples. We describe isometries on function spaces of…

Functional Analysis · Mathematics 2018-02-13 Osamu Hatori , Shiho Oi

We investigate the structure of conformal $C$-spaces,a class of Riemmanian manifolds which naturally arises as aconformal generalisation of the Einstein condition. A basic question is when such a structure is closed, or equivalently locally…

Differential Geometry · Mathematics 2008-06-05 A. Rod Gover , Paul-Andi Nagy

We find all orthogonal metrics where the geodesic Hamilton-Jacobi equation separates and the Riemann curvature tensor satisfies a certain equation (called the diagonal curvature condition). All orthogonal metrics of constant curvature…

Mathematical Physics · Physics 2015-06-19 Krishan Rajaratnam , Raymond G. McLenaghan

Robert Bryant (Theorie des varietes minimales et applications, 1988, 154: 321-347) proved that an isolated singularity of a conformal metric of positive constant curvature on a Riemann surface is a conical one. Using Complex Analysis, we…

Differential Geometry · Mathematics 2019-08-15 Jin Li , Bin Xu

We completely determine, up to homeomorphism, which simply connected compact oriented 4-manifolds admit scalar-flat, anti-self-dual Riemannian metrics. The key new ingredient is a proof that the connected sum of five reverse-oriented…

Differential Geometry · Mathematics 2007-11-13 Claude LeBrun , Bernard Maskit

In a previous paper, the first two authors classified complete Ricci-flat ALF Riemannian 4-manifolds that are toric and Hermitian, but non-Kaehler. In this article, we consider general Ricci-flat deformations of such spaces, assuming only…

Differential Geometry · Mathematics 2023-11-14 Olivier Biquard , Paul Gauduchon , Claude LeBrun

We describe the $(\alpha,\beta)$-metrics whose the $T$-tensor vanishes ($T$-condition) and the $(\alpha,\beta)$-metrics that satisfy the $\sigma T$-condition $\sigma_hT^h_{ijk}=0$, where $\sigma_h=\frac{\partial \sigma}{\partial x^h}$ and…

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

Let (M,g) be a compact Riemannian manifold with boundary. This paper is concerned with the set of scalar-flat metrics which are in the conformal class of g and have the boundary as a constant mean curvature hypersurface. We prove that this…

Differential Geometry · Mathematics 2011-05-24 Sergio Almaraz

The localization tensor is a measure of distinguishability between insulators and metals. This tensor is related to the quantum metric tensor associated with the occupied bands in momentum space. In two dimensions and in the thermodynamic…

Mesoscale and Nanoscale Physics · Physics 2020-03-18 Bruno Mera

The requirement that a (non-Einstein) K\"ahler metric in any given complex dimension $m>2$ be almost-everywhere conformally Einstein turns out to be much more restrictive, even locally, than in the case of complex surfaces. The local…

Differential Geometry · Mathematics 2007-05-23 A. Derdzinski , G. Maschler

The nonlinear equations describing all the nonsingular pencils of metrics of constant Riemannian curvature are derived and the integrability of these nonlinear equations by the method of inverse scattering problem is proved. It is proved…

Differential Geometry · Mathematics 2010-01-04 O. I. Mokhov

An $(\alpha,\beta)$-metric is defined by a Riemannian metric $\alpha$ and $1$-form $\beta$. In this paper, we study a known class of two-dimensional $(\alpha,\beta)$-metrics of vanishing S-curvature. We determine the local structure of…

Differential Geometry · Mathematics 2014-06-12 Guojun Yang

In this article we give general neccessary and sufficient conditions to ensure that a pseudo-Riemannian manifold is conformal to an Einstein space. These conditions are algorithmic in \emph{the metric tensor} whenever the Weyl endomorphism…

Differential Geometry · Mathematics 2026-01-27 Alfonso García-Parrado , Jónatan Herrera , Miguel Vadillo

In four dimensions, the most general metric admitting two Killing vectors and a rank-two Killing tensor can be parameterized by ten arbitrary functions of a single variable. We show that picking a special vierbien, reducing the system to…

General Relativity and Quantum Cosmology · Physics 2016-04-06 Andres Anabalon , Carlos Batista