首页/论文/math/0209259

arXiv math/02092592002-09-20math.DG

Families of strong KT structures in six dimensions

Anna Fino, Maurizio Parton, Simon Salamon

发表信息：: Comment. Math. Helv. 79 (2004) 317-340

英文摘要：

This paper classifies Hermitian structures on 6-dimensional nilmanifolds M=G/L for which the fundamental 2-form is d d-bar closed, a condition that is shown to depend only on the underlying complex structure J of M. The space of such J is described when G is the complex Heisenberg group, and explicit solutions are obtained from a limacon-shaped curve in the complex plane. Related theory provides examples of various types of Ricci-flat structures.

机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。

阅读原文

阅读 PDF ↗

arXiv 页面 ↗HTML 原文 ↗

本文内容

英文摘要相关论文

机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。

继续探索

相关论文

Almost-complex invariants of families of six-dimensional solvmanifolds

We compute almost-complex invariants $h^{p,0}_{\overline\partial}$, $h^{p,0}_{\text{Dol}}$ and almost-Hermitian invariants $h^{p,0}_{\barδ}$ on families of almost-Kähler and almost-Hermitian $6$-dimensional solvmanifolds. Finally, as a consequence of almost-Kähler identities we provide an obstruction to the existence of a symplectic structure on a given compact almost-complex manifold. Notice that, when $(X,J,g,ω)$ is a compact almost Hermitian manifold of real dimension greater than four, not much is known concerning the numbers $h^{p,q}_{\overline\partial}$.

2021-09-19math.DG

Left-invariant almost para-complex structures on six-dimensional nilpotent Lie groups

There are five six-dimensional nilpotent Lie groups G, which do not admit neither symplectic, nor complex structures and, therefore, can be neither almost pseudo-Kahler, nor almost Hermitian. In this work, these Lie groups are being studied. The aim of the paper is to define new left-invariant geometric structures on the Lie groups under consideration that compensate, in some sense, the absence of symplectic and complex structures. New examples of multiparametric families of metrics of signature (3,3) and almost para-complex pseudo-Riemannian half-flat structures on six-dimensional nilmanifold…

2020-01-09math.DG

One-dimensional exponential families with constant Hessian scalar curvature

We give a complete classification of 1-dimensional exponential families $\mathcal{E}$ defined over a finite space $Ω=\{x_{0}, ...,x_{n}\}$ whose Hessian scalar curvature is constant. We observe an interesting phenomenon: if $\mathcal{E}$ has constant Hessian scalar curvature, say $λ$, then $λ=\tfrac{2}{k}$ for some positive integer $k\leq m$. We also discuss the central role played by the binomial distribution in this classification.

2019-06-05math.DG

Associated Families of Immersions of Three Dimensional CR Manifolds in Euclidean Spaces

We consider isometric immersions in arbitrary codimension of three-dimensional strongly pseudoconvex pseudo-hermitian CR manifolds into the Euclidean space $\mathbb{R}^n$ and generalize in a natural way the notion of associated family. We show that the existence of such deformations turns out to be very restrictive and we give a complete classification.

2012-02-21math.DG

Two new families of Finsler connections on even-dimensional manifolds

Let $F^{2n}=(M,M',F^{\ast})$ be an even-dimensional pseudo-Finsler manifold. We construct an almost hypercomplex structure on any chart domain of a certain atlas of $M'$ by using a considered non-linear connection. Then by using the almost hypercomplex structure we define two new families of Finsler connections. Also we show that for any Finsler connection $\nabla$ there exists a linear connection $D$ such that the local almost hypercomplex structure is parallel with respect to it.

2013-05-26math.DG

Some Special Geometry in Dimension Six

We generalise the notion of contact manifold by allowing the contact distribution to have codimension two. There are special features in dimension six. In particular, we show that the complex structure on a three-dimensional complex contact manifold is determined solely by the underlying contact distribution.

2000-03-09math.DG

更多相关论文收起更多论文

Eleven-dimensional symmetric supergravity backgrounds, their geometric superalgebras, and a common reduction

We present two different families of eleven-dimensional manifolds that admit non-restricted extensions of the isometry algebras to geometric superalgebras. Both families admit points for which the superalgebra extends to a super Lie algebra; on the one hand, a family of $N=1$, $ν={}^3\!/\!_4$ supergravity backgrounds and, on the other hand, a family of $N=1$, $ν=1$ supergravity background. Furthermore, both families admit a point that can be identified with an $N=4$, $ν={}^1\!/\!_2$ six-dimensional supergravity background.

2014-08-28hep-thmath.DG

Contact metric three manifolds and Lorentzian geometry with torsion in six-dimensional supergravity

We introduce the notion of $\varepsilonη\,$-Einstein $\varepsilon\,$-contact metric three-manifold, which includes as particular cases $η\,$-Einstein Riemannian and Lorentzian (para) contact metric three-manifolds, but which in addition allows for the Reeb vector field to be null. We prove that the product of an $\varepsilonη\,$-Einstein Lorentzian $\varepsilon\,$-contact metric three-manifold with an $\varepsilonη\,$-Einstein Riemannian contact metric three-manifold carries a bi-parametric family of Ricci-flat Lorentzian metric-compatible connections with isotropic, totally skew-symmetric, cl…

2021-01-30hep-thmath.DG

Generalized geometric structures on complex and symplectic manifolds

On a smooth manifold M, generalized complex (generalized paracomplex) structures provide a notion of interpolation between complex (paracomplex) and symplectic structures on M. Given a complex manifold (M,j), we define six families of distinguished generalized complex or paracomplex structures on M. Each one of them interpolates between two geometric structures on M compatible with j, for instance, between totally real foliations and Kahler structures, or between hypercomplex and C-symplectic structures. These structures on M are sections of fiber bundles over M with typical fiber G/H for some…

2015-04-30math.DGmath.SG

Positive scalar curvature and higher-dimensional families of Seiberg-Witten equations

We introduce an invariant of tuples of commutative diffeomorphisms on a 4-manifold using families of Seiberg-Witten equations. This is a generalization of Ruberman's invariant of diffeomorphisms defined using 1-parameter families of Seiberg-Witten equations. Our invariant yields an application to the homotopy groups of the space of positive scalar curvature metrics on a 4-manifold. We also study the extension problem for families of 4-manifolds using our invariant.

2019-05-30math.DGmath.GT

球面上的无穷多族Sasaki-Einstein度量

Infinitely many families of Sasaki-Einstein metrics on spheres

本文证明了维数至少为5的奇数维标准球面及界定可平行化流形的奇数维怪球面上均存在无穷多族Sasaki-Einstein度量。

2024-06-05math.AGmath.DG

Six-dimensional spaces defined by the equations of KN and KdV

On base of three-dimensional flat metrics obtained with the help of solutions of the KdV-equation were constructed the examples of six-dimensional metrics, which are determined by the help of solutions of Krichever-Novikov and KdV. Their properties are discussed.

2014-11-04math.DGnlin.SI

球面中任意亏格极小曲面的高维族

High-Dimensional Families of Minimal Surfaces of Arbitrary Genus in Round Spheres

Mathematics Institute, University of Warwick（华威大学数学研究所）

本文在偶数维球面中构造任意亏格与共形结构的极小曲面的任意高维参数族，其维数随次数趋于无穷。

2026-09-24math.APmath.CVmath.DG

Some compatible Poisson structures and integrable bi-Hamiltonian systems on four dimensional and nilpotent six dimensional symplectic real Lie groups

We provide an alternative method for obtaining of compatible Poisson structures on Lie groups by means of the adjoint representations of Lie algebras. In this way, we calculate some compatible Poisson structures on four dimensional and nilpotent six dimensional symplectic real Lie groups. Then using Magri-Morosi's theorem we obtain new bi-Hamiltonian systems with four dimensional and nilpotent six dimensional symplectic real Lie groups as phase spaces.

2017-04-05math-phmath.DGmath.MP