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Related papers: CR manifolds admitting a CR contraction

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Let $X$ be a CR manifold with transversal, proper CR $G$-action. We show that $X/G$ is a complex space such that the quotient map is a CR map. Moreover the quotient is universal, i.e. every invariant CR map into a complex manifold…

Complex Variables · Mathematics 2020-02-04 Kevin Fritsch , Peter Heinzner

We obtain an embedding theorem for compact strongly pseudoconvex CR manifolds which are bounadries of some complete Hermitian manifolds. We use this to compactify some negatively curved Kaehler manifolds with compact strongly pseudoconvex…

Complex Variables · Mathematics 2015-09-10 G. Marinescu , N. Yeganefar

We give a holomorphic extension result from non generic CR submanifold of $\C^L$ of positive CR dimension. We consider $N$ a non generic CR submanifold given by $N=\{\n,h(\n)\}$ where $\n$ is a generic submanifold of some $\C^{\ell}$ and…

Complex Variables · Mathematics 2007-05-23 Nicolas Eisen

Let $M$ be the image of a smooth CR embedding of a strictly pseudoconvex CR real hypersurface into a sphere. If the CR second fundamental form of $M$ vanishes, we show that $M$ is a totally geodesic submanifold.

Complex Variables · Mathematics 2015-05-14 Shanyu Ji , Yuan Yuan

We consider a smooth CR mapping $f$ from a real-analytic generic submanifold $M$ in $\bC^N$ into $\bC^N$. For $M$ of finite type and essentially finite at a point $p\in M$, and $f$ formally finite at $p$, we give a necessary and sufficient…

Complex Variables · Mathematics 2007-05-23 Peter Ebenfelt , Linda P. Rothschild

In this paper we prove new embedding results for compactly supported deformations of $CR$ submanifolds of $\mathbb{C}^{n+d}$: We show that if $M$ is a $2$-pseudoconcave $CR$ submanifold of type $(n,d)$ in $\mathbb{C}^{n+d}$, then any…

Complex Variables · Mathematics 2019-05-29 Judith Brinkschulte , C. Denson Hill

We study the normal holonomy group, i.e. the holonomy group of the normal connection, of a CR-submanifold of a complex space form. We complete the local classification of normal holonomies for complex submanifolds. We show that the normal…

Differential Geometry · Mathematics 2015-05-05 Antonio J. Di Scala , Francisco Vittone

In this paper we introduce the concept of inflexible $CR$ submanifolds. These are $CR$ submanifolds of some complex Euclidean space such that any compactly supported $CR$ deformation is again globally $CR$ embeddable into some complex…

Complex Variables · Mathematics 2018-07-25 Judith Brinkschulte , C. Denson Hill

We study a germ of real analytic n-dimensional submanifold of C n that has a complex tangent space of maximal dimension at a CR singularity. Under some assumptions , we show its equivalence to a normal form under a local biholomorphism at…

Complex Variables · Mathematics 2016-12-21 Xianghong Gong , Laurent Stolovitch

Given any real-analytic CR manifold M, we provide general conditions on M guaranteeing that the group of all its global real-analytic CR automorphisms is a Lie group (in an appropriate topology). Our conditions are in particular satisfied…

Complex Variables · Mathematics 2009-01-12 Bernhard Lamel , Nordine Mir , Dmitri Zaitsev

It is shown that any smooth closed orientable manifold of dimension $2k + 1$, $k \geq 2$, admits a smooth polynomially convex embedding into $\mathbb C^{3k}$. This improves by $1$ the previously known lower bound of $3k+1$ on the possible…

Complex Variables · Mathematics 2020-09-29 Purvi Gupta , Rasul Shafikov

We classify the Lie algebras of infinitesimal CR automorphisms of weakly pseudoconvex hypersurfaces of finite multitype in $\mathbb C^N$. In particular, we prove that such manifolds admit neither nonlinear rigid automorphisms, nor real or…

Complex Variables · Mathematics 2022-03-23 Shin-Young Kim , Martin Kolar

We study normal CR compact manifolds in dimension 3. For a choice of a CR Reeb vector field, we associate a Sasakian metric on them, and we classify those metrics. As a consequence, the underlying manifolds are topologically finite quotiens…

Differential Geometry · Mathematics 2007-05-23 F. A. Belgun

Let $M$ be a $CR$ submanifold of a complex manifold $X$. The main result of this article is to show that $CR$-hypoellipticity at $p_0\in{M}$ is necessary and sufficient for holomorphic extension of all germs of $CR$ functions to an ambient…

Complex Variables · Mathematics 2011-11-08 Mauro Nacinovich , Egmont Porten

Let M be an orbit of a real semisimple Lie group G_0 acting on a complex a flag manifolds G/Q of its complexification G. We study the space of global CR functions on M and characterize those M which are strictly locally CR separable, i.e.…

Complex Variables · Mathematics 2007-05-23 Andrea Altomani

We study regularity properties of CR maps in positive codimension valued in pseudoconvex manifolds which carry a nontrivial Levi foliation. We introduce an invariant which can be used to deduce that any sufficiently regular CR map from a…

Complex Variables · Mathematics 2023-02-28 Josef Greilhuber , Bernhard Lamel

Let $M$ be a $CR$ submanifold of a complex manifold $X$. The main result of this article is to show that $CR$-hypoellipticity at $p_0\in{M}$ is necessary and sufficient for holomorphic extension of all germs of $CR$ functions to an ambient…

Complex Variables · Mathematics 2012-01-10 Mauro Nacinovich , Egmont Porten

In this note, we consider submanifolds of a generalized K\"ahler manifold that are CR-submanifolds for the two associated Hermitian structures. Then, we establish the conditions for the induced, generalized F structure to be a CRFK…

Differential Geometry · Mathematics 2017-08-07 Izu Vaisman

In this paper we study the geometry of complete constant mean curvature (CMC) hypersurfaces immersed in an (n + 1)-dimensional Riemannian manifold N (n = 2, 3 and 4) with sectional curvatures uniformly bounded from below. We generalise…

Differential Geometry · Mathematics 2025-01-07 Giuseppe Tinaglia , Alex Zhou

It is constructed a normal form for a class of real-smooth surfaces M\subset\mathbb{C}^{2} defined near a degenerate CR singularity.

Complex Variables · Mathematics 2026-05-26 Valentin Burcea