activity
20102022
most citedA new characterization of the CR shpere and the sharp eigenvalue estimate for the Kohn Laplacian

20 citations · 90 across the 21 of their papers we have counts for

collaborators

21 papers

math.CV2022

On highly degenerate CR maps of spheres

Giuseppe della Sala, Bernhard Lamel, Michael Reiter +1

For we classify the -degenerate smooth CR maps of the three-dimensional unit sphere into the -dimensional unit sphere. Each of these maps has image being…

math.CV2022

The CR umbilical locus of a real ellipsoid in

Duong Ngoc Son

This paper concerns the CR umbilical locus of a real ellipsoid in , the set of points at which the ellipsoid can be osculated by a biholomorphic image of the sphere u…

math.CV2021★ 2 cited

An upper bound for the first positive eigenvalue of the Kohn Laplacian on Reinhardt real hypersurfaces

Gian Maria Dall'Ara, Duong Ngoc Son

A real hypersurface in is said to be Reinhardt if it is invariant under the standard -action on . Its CR geometry can be described in ter…

math.CV2021★ 5 cited

On CR maps from the sphere into the tube over the future light cone

Michael Reiter, Duong Ngoc Son

We determine all local smooth or formal CR maps from the unit sphere into the tube $\mathcal{T}:= \mathcal{C} \times i\mathbb{R}^3 \subset \mathb…

math.CV2020

The holomorphic sectional curvature and "convex" real hypersurfaces in Kähler manifolds

Duong Ngoc Son

We prove a sharp lower bound for the Tanaka-Webster holomorphic sectional curvature of strictly pseudoconvex real hypersurfaces that are "semi-isometrically" immersed in a Kähler m…

math.DG2020★ 3 cited

The -Operator and Real Holomorphic Vector Fields

Friedrich Haslinger, Duong Ngoc Son

Let be a Hermitian manifold and a smooth weight function on . The -complex on weighted Bergman spaces of holomorphic -for…

math.CV2019★ 4 cited

The CR Ahlfors derivative and a new invariant for spherically equivalent CR maps

Bernhard Lamel, Duong Ngoc Son

We study a CR analogue of the Ahlfors derivative for conformal immersions of Stowe [23] that generalizes the CR Schwarzian derivative studied earlier by the second-named author [21…

math.CV2019★ 2 cited

On the Chern-Moser-Weyl tensor of real hypersurfaces

Michael Reiter, Duong Ngoc Son

We derive an explicit formula for the well-known Chern-Moser-Weyl tensor for nondegenerate real hypersurfaces in complex space in terms of their defining functions. The formula is…

math.CV2019★ 1 cited

Semi-isometric CR immersions of CR manifolds into Kähler manifolds and applications

Duong Ngoc Son

We study the second fundamental form of semi-isometric CR immersions from strictly pseudoconvex CR manifolds into Kähler manifolds. As an application, we give a precise condition f…

math.CV2019★ 1 cited

Eigenvalues of the Kohn Laplacian and deformations of pseudohermitian structures on CR manifolds

Amine Aribi, Duong Ngoc Son

We study the eigenvalues of the Kohn Laplacian on a closed embedded strictly pseudoconvex CR manifold as functionals on the set of positive oriented pseudohermitian structures $\ma…

math.CV2017★ 7 cited

CR-Analogue of Siu--formula and Applications to Rigidity problem for pseudo-Hermitian harmonic maps

Song-Ying Li, Duong Ngoc Son

We give several versions of Siu's -formula for maps from a strictly pseudoconvex pseudo-Hermitian manifold into a Kähler manifold …

math.CV2016★ 4 cited

The sharp upper bounds for the first positive eigenvalue of the Kohn-Laplacian on compact strictly pseudoconvex hypersurfaces

Song-Ying Li, Guijuan Lin, Duong Ngoc Son

We give sharp and explicit upper bounds for the first positive eigenvalue of the Kohn-Laplacian on compact strictly pseudoconvex hypersurfaces in i…

math.CV2016★ 6 cited

A family of compact strictly pseudoconvex hypersurfaces in without umbilical points

Peter Ebenfelt, Duong Ngoc Son, Dmitri Zaitsev

We prove the following: For , let be the bounded strictly pseudoconvex domain in given by \begin{equation*} (\log|z|)^2+(\log|w|)^2<ε^2. \end{equation*} Th…

math.CV2015★ 3 cited

The Schwarzian derivative and Möbius equation on strictly pseudo-convex CR manifolds

Duong Ngoc Son

The notion of Schwarzian derivative for locally univalent holomorphic functions on complex plane was generalized for conformal diffeomorphisms by Osgood and Stowe in 1992 [27]. We…

math.CV2015★ 3 cited

Umbilical points on three dimensional strictly pseudoconvex CR manifolds. I. Manifolds with -action

Peter Ebenfelt, Duong Ngoc Son

The question of existence of umbilical points, in the CR sense, on compact, three dimensional, strictly pseudoconvex CR manifolds was raised in the seminal paper by S.-S. Chern and…

math.DG2013★ 20 cited

A new characterization of the CR shpere and the sharp eigenvalue estimate for the Kohn Laplacian

Song-Ying Li, Duong Ngoc Son, Xiaodong Wang

Motivated by a sharp eigenvalue estimate for the Kohn Laplacian, we prove a theorem that characterizes the CR sphere in terms of the existence of a non-trivial complex-valued funct…

math.CV2012★ 2 cited

Holomorphic mappings between pseudoellipsoids in different dimensions

Peter Ebenfelt, Duong Ngoc Son

We give a necessary and sufficient condition for the existence of nondegenerate holomorphic mappings between pseudoellipsoidal real hypersurfaces, and provide an explicit parametri…

math.CV2012★ 10 cited

On the existence of holomorphic embeddings of strictly pseudoconvex algebraic hypersurfaces into spheres

Peter Ebenfelt, Duong Son

We show that there are strictly pseudoconvex, real algebraic hypersurfaces in $\bC^{n+1}$ that cannot be locally embedded into a sphere in $\bC^{N+1}$ for any . In fact, we show…

math.CV2012★ 9 cited

CR singular images of generic submanifolds under holomorphic maps

Jiri Lebl, André Minor, Ravi Shroff +2

The purpose of this paper is to organize some results on the local geometry of CR singular real-analytic manifolds that are images of CR manifolds via a CR map that is a diffeomorp…

math.CV2011★ 3 cited

Transversality of holomorphic mappings between real hypersurfaces in complex spaces of different dimensions

Peter Ebenfelt, Duong Ngoc Son

We consider holomorphic mappings between a smooth real hypersurface $M\subset \bC^{n+1}$ and another $M'\subset \bC^{N+1}$ with . We provide conditions guaranteeing th…

math.CV2010★ 5 cited

CR transversality of holomorphic mappings between generic submanifolds in complex spaces

Peter Ebenfelt, Duong Ngoc Son

We show that a holomorphic mapping sending one generic submanifold into another of the same dimension is CR transversal to the target submanifold provided that the source manifold…