English
Related papers

Related papers: Normal forms of para-CR hypersurfaces

200 papers

In this paper, we study generic conformally flat hypersurfaces in the Euclidean $4$-space $\mathbb{R}^4$ using the framework of M\"{o}bius geometry. First, we classify locally the generic conformally flat hypersurfaces with closed M\"obius…

Differential Geometry · Mathematics 2017-09-07 Xiu Ji , Tongzhu Li

This paper addresses two questions related to mapping problems. In the first part of the paper, we discuss some recent results regarding the $2$-jet determination for biholomorphisms between smooth (weakly) pseudoconvex hypersurfaces; in…

Complex Variables · Mathematics 2025-06-27 Florian Bertrand , Martin Kolář , Francine Meylan

We prove that any piece of a rotational hypersurface with prescribed mean curvature function in a Euclidean space can be uniquely extended infinitely, which generalizes the results by Euler and Delaunay for surfaces of revolution with…

Differential Geometry · Mathematics 2013-07-12 Katsuei Kenmotsu , Takeyuki Nagasawa

We study the non-embddability property for a class of real hypersurfaces, called real hypersurfaces of involution type, into the sphere in the low codimensional case, by making use of property of a naturally related Gauss curvature. We also…

Complex Variables · Mathematics 2012-10-16 Xiaojun Huang , Shanyu Ji , Brandon Lee

The hypersurface is one of the most important objects in a space. Many authors studied diffrent geometric aspects of hypersurfaces in a space. In this paper, we define three types of 2-ruled hypersurfaces in a Walker 4-manfold E 41 . We…

Differential Geometry · Mathematics 2025-08-15 Mohamed Ayatola Dramé , Ameth Ndiaye , Abdoul Salam Diallo

We examine, in a purely geometrical way, static Ricci-flat 5-manifolds admitting the 2-sphere and an additional hypersurface-orthogonal Killing vector. These are widely studied in the literature, from different physical approaches, and…

General Relativity and Quantum Cosmology · Physics 2009-11-11 Kayll Lake

We derive global curvature estimates for closed, strictly star-shaped $(n-2)$-convex hypersurfaces in warped product manifolds, which satisfy the prescribed $(n-2)$-curvature equation with a general right-hand side. The proof can be readily…

Analysis of PDEs · Mathematics 2024-11-18 Bin Wang

Let $H \subset {\mathbb P}^n$ be a real-analytic subvariety of codimension one induced by a real-analytic curve in the Grassmannian $G(n+1,n)$. Assuming $H$ has a global defining function, we prove $H$ is Levi-flat, the closure of its…

Complex Variables · Mathematics 2015-05-14 Jiri Lebl

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

We address the problem of determining the hypersurfaces $f\colon M^{n} \to \mathbb{Q}_s^{n+1}(c)$ with dimension $n\geq 3$ of a pseudo-Riemannian space form of dimension $n+1$, constant curvature $c$ and index $s\in \{0, 1\}$ for which…

Differential Geometry · Mathematics 2015-08-12 S. Canevari , R. Tojeiro

We consider hypersurfaces in the real Euclidean space $\mathbb{R}^{n+1}$ ($n\geq2$) which are relatively normalized. We give necessary and sufficient conditions a) for a surface of negative Gaussian curvature in $\mathbb{R}^3$ to be ruled,…

Differential Geometry · Mathematics 2014-04-08 Stylianos Stamatakis , Ioannis Kaffas , Ioanna-Iris Papadopoulou

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 the condition that its complexification admits the maximum number of deck transformations,…

Complex Variables · Mathematics 2016-10-12 Xianghong Gong , Laurent Stolovitch

In this paper we study biconservative hypersurfaces $M$ in space forms $\overline M^{n+1}(c)$ with four distinct principal curvatures whose second fundamental form has constant norm. We prove that every such hypersurface has constant mean…

Differential Geometry · Mathematics 2024-09-16 Ram Shankar Gupta , Andreas Arvanitoyeorgos

In this manuscript we establish local H\"older regularity estimates for bounded solutions of a certain class of doubly degenerate evolution PDEs. By making use of intrinsic scaling techniques and geometric tangential methods, we derive…

Analysis of PDEs · Mathematics 2021-03-17 J. V. Silva , Elzon C. Júnior , Gleydson C. Ricarte

We construct a finitely dimensional invariant manifold of holomorphic discs attached to a certain class of smooth pseudconvex hypersurfaces of finite type in $\C^2$, generalizing the notion of stationary discs. The discs we construct are…

Complex Variables · Mathematics 2013-08-01 Florian Bertrand , Giuseppe Della Sala

We study holomorphic foliations tangent to singular real-analytic Levi-flat hypersurfaces in compact complex manifolds of complex dimension two. We give some hypotheses to guarantee the existence of dicritical singularities of these…

Complex Variables · Mathematics 2018-10-16 Andrés Beltrán , Arturo Fernández-Pérez , Hernán Neciosup

In this paper, we study a second order variational problem for locally convex hypersurfaces, which is the affine invariant analogue of the classical Plateau problem for minimal surfaces. We prove existence, regularity and uniqueness results…

Differential Geometry · Mathematics 2007-05-23 Neil S. Trudinger , Xu-Jia Wang

In the previous paper, it has been proved that the generalized rotational hypersurfaces of O(n-1)-type and O (l+1) x O(m+1)-type, for which the mean curvature is any prescribed continuous function. This paper is a sequel, and a similar…

Differential Geometry · Mathematics 2013-07-12 Takeyuki Nagasawa

Given a smooth curve $\gamma$ in some $m$-dimensional surface $M$ in $\mathbb{R}^{m+1}$, we study existence and uniqueness of a flat surface $H$ having the same field of normal vectors as $M$ along $\gamma$, which we call a flat…

Differential Geometry · Mathematics 2023-07-11 Irina Markina , Matteo Raffaelli

Consider a constant mean curvature immersion $F:U(\subset \boldsymbol{R}^n)\to M$ into an arbitrary Lorentzian $(n+1)$-manifold $M$. A point $o\in U$ is called a light-like point if the first fundamental form $ds^2$ of $F$ degenerates at…

Differential Geometry · Mathematics 2018-11-06 Masaaki Umehara , Kotaro Yamada