English
Related papers

Related papers: CR Yamabe constant and inequivalent CR structures

200 papers

In this paper, we study the CR Yamabe flow with zero CR Yamabe invariant. We use the CR Poincar\'e inequality and a Gagliardo-Nirenberg type interpolation inequality to show that this flow has long time solution and the solution converges…

Differential Geometry · Mathematics 2018-07-25 Weimin Sheng , Kunbo Wang

For a closed Riemannian manifold of dimension $n\geq 3$ and a subgroup $G$ of the isometry group, we define and study the $G-$equivariant second Yamabe constant and we obtain some results on the existence of $G-$invariant nodal solutions of…

Differential Geometry · Mathematics 2018-01-11 Guillermo Henry , Farid Madani

Contact Riemannian manifolds, whose complex structures are not necessarily integrable, are generalization of pseudohermitian manifolds in CR geometry. The Tanaka-Webster-Tanno connection plays the role of the Tanaka-Webster connection of a…

Differential Geometry · Mathematics 2015-01-28 Feifan Wu , Wei Wang

We study the stability of the embeddability of compact 2-concave CR manifolds in complex manifolds under small horizontal perturbations of the CR structure.

Complex Variables · Mathematics 2012-03-23 Christine Laurent-Thiébaut

In this work, we study the convergence of the normalized Yamabe flow with positive Yamabe constant on a class of pseudo-manifolds that includes stratified spaces with iterated cone-edge metrics. We establish convergence under a low energy…

Differential Geometry · Mathematics 2025-08-25 Gilles Carron , Jørgen Olsen Lye , Boris Vertman

For a compact manifold $M$ of $\dim M =n\geq 4$, we study two conformal invariants of a conformal class $C$ on $M$. These are the Yamabe constant $Y_C(M)$ and the $L^{\frac{n}{2}}$-norm $W_C(M)$ of the Weyl curvature. We prove that for any…

Differential Geometry · Mathematics 2007-05-23 Kazuo Akutagawa , Boris Botvinnik , Osamu Kobayashi , Harish Seshadri

We consider a compact pseudo-hermitian manifold (M,\theta, J), that is a manifold equipped with a contact form \theta and CR structure J. We consider a conformal deformation of the contact form to obtain a complete, singular contact form…

Differential Geometry · Mathematics 2025-04-10 Sagun Chanillo , Paul C. Yang

The Yamabe Invariant of a smooth compact manifold is by definition the supremum of the scalar curvatures of unit-volume Yamabe metrics on the manifold. For an explicit infinite class of 4-manifolds, we show that this invariant is positive…

dg-ga · Mathematics 2008-02-03 Matthew J. Gursky , Claude LeBrun

In this paper, we solve the so-called CR Poincar\'e-Lelong equation by solving the CR Poisson equation on a complete noncompact CR $(2n+1)$-manifold with nonegative pseudohermitian bisectional curvature tensors and vanishing torsion which…

Differential Geometry · Mathematics 2018-04-12 Der-Chen Chang , Shu-Cheng Chang , Yingbo Han , Chien Lin

An explicit classification of simply connected compact homogeneous CR manifolds G/L of codimension one, with non-degenerate Levi form, is given. There are three classes of such manifolds: a) the standard CR homogeneous manifolds which are…

Differential Geometry · Mathematics 2007-05-23 Dmitry V. Alekseevsky , Andrea F. Spiro

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

The Yamabe invariant is a diffeomorphism invariant of smooth compact manifolds that arises from the normalized Einstein-Hilbert functional. This article highlights the manner in which one compelling open problem regarding the Yamabe…

Differential Geometry · Mathematics 2023-05-09 Claude LeBrun

The CR analogue of B.-Y. Chen's conjecture on pseudo biharmonic maps will be shown. Pseudo biharmonic, but not pseudo harmonic, isometric immersions with parallel pseudo mean curvature vector fields, will be characterized. Several examples…

Differential Geometry · Mathematics 2014-10-02 Hajime Urakawa

Dimension four provides a peculiarly idiosyncratic setting for the interplay between scalar curvature and differential topology. Here we will explain some of the peculiarities of the four-dimensional realm via a careful discussion of the…

Differential Geometry · Mathematics 2021-12-22 Claude LeBrun

We study pseudo Yang-Mills fields on a compact strictly pseudoconvex CR manifold.

Differential Geometry · Mathematics 2015-06-26 Elisabetta Barletta , Sorin Dragomir , Hajime Urakawa

We study the existence problem for complete contact forms with constant Tanaka--Webster scalar curvature on non-compact strictly pseudoconvex CR manifolds. We prove that, under mild assumptions, the universal cover of a compact strictly…

Differential Geometry · Mathematics 2026-02-04 Jeffrey S. Case , Yuya Takeuchi

We prove the existence of a solution of the Yamabe equation on complete manifolds with finite volume and positive Yamabe invariant. In order to circumvent the standard methods on closed manifolds which heavily rely on global (compact)…

Differential Geometry · Mathematics 2011-11-11 Nadine Große

A complex filling of a CR manifold is said to be equivariant with respect to a CR action if the action extends to a smooth action by biholomorphisms on the whole filling. Under a noncompactness condition for the action, we describe all…

Differential Geometry · Mathematics 2009-01-05 Benoit Kloeckner

We introduce the notion of pseudohermitian k-curvature, which is a natural extension of the Webster scalar curvature, on an orientable manifold endowed with a strictly pseudoconvex pseudohermitian structure (referred here as a CR manifold)…

Differential Geometry · Mathematics 2012-05-10 Ezequiel Barbosa , Luiz Gustavo Carneiro , Marcos Montenegro

We continue our previous work studying critical exponent semilinear elliptic (and subelliptic) problems which generalize the classical Yamabe problem. In [3] the focus was on metric-measure spaces with an `almost smooth' structure, with…

Differential Geometry · Mathematics 2013-06-20 Kazuo Akutagawa , Gilles Carron , Rafe Mazzeo