English
Related papers

Related papers: A classification of spherical symmetric CR manifol…

200 papers

We study non-degenerate CR geometries of hypersurface type that are symmetric in the sense that, at each point, there is a CR transformation reversing the CR distribution at that point. We show that such geometries are either flat or…

Complex Variables · Mathematics 2018-08-10 Jan Gregorovič , Lenka Zalabová

In this paper, we consider a non-degenerate CR manifold (M,H(M),J) with a given pseudo-Hermitian 1-form {\theta}, and endow the CR distribution H(M) with any Hermitian metric h instead of the Levi form L_{{\theta}}. This induces a natural…

Differential Geometry · Mathematics 2024-08-21 Yuxin Dong , Yibin Ren

We study some basic properties and examples of Hermitian metrics on complex manifolds whose traces of the curvature of the Chern connection are proportional to the metric itself.

Differential Geometry · Mathematics 2020-07-22 Daniele Angella , Simone Calamai , Cristiano Spotti

We define pseudo-Hermitian magnetic curves in Sasakian manifolds endowed with the Tanaka-Webster connection. After we give a complete classification theorem, we construct parametrizations of pseudo-Hermitian magnetic curves in…

Differential Geometry · Mathematics 2021-03-02 Şaban Güvenç , Cihan Özgür

We prove and organize some results on the normal forms of Hermitian operators composed with the Veronese map. We apply this general framework to prove two specific theorems in CR geometry. First, extending a theorem of Faran, we classify…

Complex Variables · Mathematics 2011-11-16 Jiri Lebl

We consider the class of compact Hermitian manifolds whose Chern connection is Ambrose-Singer, namely, it has parallel torsion and curvature. We prove structure theorems for such manifolds.

Differential Geometry · Mathematics 2023-08-02 Lei Ni , Fangyang Zheng

We give a classification of compact conformally Kahler Einstein-Weyl manifolds whose Ricci tensor is hermitian.

Differential Geometry · Mathematics 2016-02-25 Wlodzimierz Jelonek

By variational methods, for a kind of Webster scalar curvature problems on the CR sphere with cylindrically symmetric curvature, we construct some multi-peak solutions as the parameter is sufficiently small under certain assumptions. We…

Analysis of PDEs · Mathematics 2008-11-27 Daomin Cao , Shuangjie Peng , Shusen Yan

A quasi-Hamiltonian manifold is called multiplicity free if all of its symplectic reductions are 0-dimensional. In this paper, we classify compact, multiplicity free, twisted quasi-Hamiltonian manifolds for simply connected, compact Lie…

Differential Geometry · Mathematics 2025-01-13 Friedrich Knop

In this paper, we consider some generalized holomorphic maps between pseudo-Hermitian manifolds. These maps include the \emph{CR} maps and the transversally holomorphic maps. In terms of some sub-Laplacian or Hessian type Bochner formulas,…

Differential Geometry · Mathematics 2019-09-13 Yuxin Dong , Yibin Ren , Weike Yu

Properties of Hermitian forms are used to investigate several natural questions from CR Geometry. To each Hermitian symmetric polynomial we assign a Hermitian form. We study how the signature pairs of two Hermitian forms behave under the…

Complex Variables · Mathematics 2011-10-20 John P. D'Angelo , Jiri Lebl

We investigate several classes of submanifolds of almost quaternionic skew-Hermitian manifolds $(M^{4n}, Q, \omega)$, including almost symplectic, almost complex, almost pseudo-Hermitian and almost quaternionic submanifolds. In the…

Differential Geometry · Mathematics 2026-01-07 Ioannis Chrysikos , Jan Gregorovič

A "hidden symmetry" of a Riemannian manifold M is an isometry of a d-sheeted, 1<d<\infty, Riemannian cover of M which is not the lift of any isometry. In this paper we characterize the locally symmetric metric(s) on a closed, arithmetic…

Differential Geometry · Mathematics 2007-05-23 Benson Farb , Shmuel Weinberger

We discuss the problem of classifying all local CR diffeomorphisms of a strictly pseudoconvex surface. Our method exploits the Tanaka--Webster pseudohermitian invariants, their transformation formulae, and the Chern--Moser invariants. Our…

Complex Variables · Mathematics 2011-03-07 Roberto Monti , Daniele Morbidelli

We show that if a simply connected manifold is almost quarter pinched then it is diffeomorphic to a CROSS (a compact rank one symmetric space) or a sphere.

Differential Geometry · Mathematics 2008-07-14 Peter Petersen , Terence Tao

In this paper we classify Ricci-generalized pseudosymmetric $(\kappa, \mu)$-contact metric manifolds in the sense of Deszcz .

Differential Geometry · Mathematics 2017-08-22 N. Malekzadeh , E. Abedi

This is a final step in a local classification of pseudo-Riemannian manifolds with parallel Weyl tensor that are not conformally flat or locally symmetric.

Differential Geometry · Mathematics 2009-03-06 Andrzej Derdzinski , Witold Roter

In this paper, we deal with a strongly pseudoconvex almost CR manifold with a CR contraction. We will prove that the stable manifold of the CR contaction is CR equivalent to the Heisenberg group model.

Complex Variables · Mathematics 2022-08-04 Jae-Cheon Joo , Kang-Hyurk Lee

We classify the normal CR structures on $S^3$ and their automorphism groups. Together with [3], this closes the classification of normal CR structures on contact 3-manifolds. We give a criterion to compare 2 normal CR structures, and we…

Differential Geometry · Mathematics 2007-05-23 Florin Alexandru Belgun

In our previous work, we introduced a special type of Hermitian metrics called {\em torsion-critical,} which are non-K\"ahler critical points of the $L^2$-norm of Chern torsion over the space of all Hermitian metrics with unit volume on a…

Differential Geometry · Mathematics 2025-04-09 Dongmei Zhang , Fangyang Zheng