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相关论文: The Sasakian Geometry of the Heisenberg Group

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We study the Sasaki cone of a CR structure of Sasaki type on a given closed manifold. We introduce an energy functional over the cone, and use its critical points to single out the strongly extremal Reeb vectors fields. Should one such…

微分几何 · 数学 2009-11-23 Charles P. Boyer , Krzysztof Galicki , Santiago R. Simanca

In this paper we study the Sasakian geometry on S^3-bundles over a Riemann surface of genus g>0 with emphasis on extremal Sasaki metrics. We prove the existence of a countably infinite number of inequivalent contact structures on the total…

微分几何 · 数学 2015-01-14 Charles P. Boyer , Christina W. Tønnesen-Friedman

Using the Sasakian join construction with homology 3-spheres, we give a countably infinite number of examples of Sasakian manifolds with perfect fundamental group in all odd dimensions greater than 1. These have extremal Sasaki metrics with…

微分几何 · 数学 2013-09-30 Charles P. Boyer , Christina W. Tønnesen-Friedman

We prove that a compact Sasakian manifolds whose first and second basic Chern classes vanish is locally isomorphic to the real Heisenberg group equipped with the standard left invariant Sasakian structure up to deformation associated to a…

微分几何 · 数学 2023-10-20 Indranil Biswas , Hisashi Kasuya

We propose a new approach to the existence of constant transversal scalar curvature Sasaki structures drawing on ideas and tools from the CR Yamabe problem, establishing a link between the CR Yamabe invariant, the existence of Sasaki…

微分几何 · 数学 2025-09-03 Abdellah Lahdili , Eveline Legendre , Carlo Scarpa

The purpose of this paper is to study the Sasakian geometry on odd dimensional sphere bundles over a smooth projective algebraic variety $N$ with the ultimate, but probably unachievable goal of understanding the existence and non-existence…

微分几何 · 数学 2021-09-29 Charles P. Boyer , Christina W. Tønnesen-Friedman

We establish an equivalence between conformally Einstein--Maxwell Kahler 4-manifolds (recently studied in many works) and extremal Kahler 4-manifolds (in the sense of Calabi) with nowhere vanishing scalar curvature. The corresponding pairs…

微分几何 · 数学 2019-01-07 Vestislav Apostolov , David M. J. Calderbank

Measure contraction properties are generalizations of the notion of Ricci curvature lower bounds in Riemannian geometry to more general metric measure spaces. In this paper, we give sufficient conditions for a Sasakian manifold equipped…

微分几何 · 数学 2014-11-11 Paul W. Y. Lee , Chengbo Li , Igor Zelenko

We describe a general procedure for constructing new Sasaki metrics of constant scalar curvature from old ones. Explicitly, we begin with a regular Sasaki metric of constant scalar curvature on a 2n+1-dimensional compact manifold M and…

微分几何 · 数学 2016-08-23 Charles P. Boyer , Christina W. Tønnesen-Friedman

In previous work (arXiv:2205.12067), we defined a notion of a generalized Sasakian structure in the context of generalized contact geometry, the odd dimensional analogue of generalized complex geometry introduced by Hitchin and Gualtieri.…

微分几何 · 数学 2024-08-27 Janet Talvacchia

Let $M$ be a closed manifold of Sasaki type. A polarization of $M$ is defined by a Reeb vector field, and for one such, we consider the set of all Sasakian metrics compatible with it. On this space, we study the functional given by the…

微分几何 · 数学 2008-11-26 Charles P. Boyer , Krzysztof Galicki , Santiago R. Simanca

We show that the standard picture regarding the notion of stability of constant scalar curvature metrics in K\"ahler geometry described by S.K. Donaldson, which involves the geometry of infinite-dimensional groups and spaces, can be applied…

微分几何 · 数学 2011-08-19 Weiyong He

The main purpose of this work is to generalize the $S^3_\bfw$ Sasaki join construction $M\star_\bfl S^3_\bfw$ described in \cite{BoTo14a} when the Sasakian structure on $M$ is regular, to the general case where the Sasakian structure is…

微分几何 · 数学 2023-03-22 Charles P. Boyer , Christina W. Tønnesen-Friedman

In this note, we describe the geometry of the quaternionic Heisenberg groups from a Riemannian viewpoint. We show, in all dimensions, that they carry an almost $3$-contact metric structure which allows us to define the metric connection…

微分几何 · 数学 2015-10-28 Ilka Agricola , Ana Cristina Ferreira , Reinier Storm

In this paper, we study the geometry and topology of complete gradient shrinking Sasaki-Ricci solitons. We first prove that they must be connected at infinity. This is a Sasaki analogue of gradient shrinking K\"ahler-Ricci solitons.…

微分几何 · 数学 2026-04-16 Shu-Cheng Chang , Yingbo Han , Chin-Tung Wu

We show that the standard definitions of Sasaki structures have elegant and simplifying interpretations in terms of projective differential geometry. For Sasaki-Einstein structures we use projective geometry to provide a resolution of such…

微分几何 · 数学 2019-12-09 A. Rod Gover , Katharina Neusser , Travis Willse

A positive answer is given to the existence of Sasakian structures on the tangent sphere bundle of some Riemannian manifold whose sectional curvature is not constant. Among other results, it is proved that the tangent sphere bundle Tr(G/K),…

微分几何 · 数学 2021-05-27 J. C. González-Dávila

We discuss the existence and non-existence of constant scalar curvature, as well as extremal, Sasaki metrics. We prove that the natural Sasaki-Boothby-Wang manifold over the admissible projective bundles over local products of non-negative…

Extending the work of G. Sz\'ekelyhidi and T. Br\"onnle to Sasakian manifolds we prove that a small deformation of the complex structure of the cone of a constant scalar curvature Sasakian manifold admits a constant scalar curvature…

微分几何 · 数学 2015-12-01 Carl Tipler , Craig van Coevering

In this paper, we concern with the Sasaki analogue of Yau uniformization conjecture in a complete noncompact Sasakian manifold with nonnegative transverse bisectional curvature. As a consequence, we confirm that any $5$-dimensional complete…

微分几何 · 数学 2026-01-16 Shu-Cheng Chang , Yingbo Han , Chien Lin , Chin-Tung Wu
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