Hypersurfaces of prescribed curvature in Lorentzian manifolds

Hypersurfaces with Light-Like Points in a Lorentzian Manifold II

In the authors' previous work, it was shown that if a zero mean curvature $C^4$-differentiable hypersurface in an arbitrarily given Lorentzian manifold admits a degenerate light-like point, then the hypersurface contains a light-like geodesic segment passing through the point. The purpose of this paper is to point out that the same conclusion holds with just $C^3$-differentiability of the hypersurfaces.

Some classifications of biharmonic Lorentzian hypersurfaces in Minkowski 5-space $\mathbb E^5_1$

In this paper, we study Lorentzian hypersurfaces in Minkowski 5-space with non-diagonalizable shape operator whose characteristic polinomial is $(t-k_1)^2(t-k_3)(t-k_4)$ or $(t-k_1)^3(t-k_4)$. We proved that in these cases, a hypersurface is biharmonic if and only if it is minimal.

Hypersurfaces of prescribed scalar curvature in Lorentzian manifolds

The existence of closed hypersurfaces of prescribed scalar curvature in globally hyperbolic Lorentzian manifolds is proved provided there are barriers.

Hypersurfaces of prescribed mean curvature in Lorentzian manifolds

We give a new existence proof for closed hypersurfaces of prescribed mean curvature in Lorentzian manifolds.

On geometry of hypersurfaces of a pseudoconformal space of Lorentzian signature

There are three types of hypersurfaces in a pseudoconformal space C^n_1 of Lorentzian signature: spacelike, timelike, and lightlike. These three types of hypersurfaces are considered in parallel. Spacelike hypersurfaces are endowed with a proper conformal structure, and timelike hypersurfaces are endowed with a conformal structure of Lorentzian type. Geometry of these two types of hypersurfaces can be studied in a manner that is similar to that for hypersurfaces of a proper conformal space. Lightlike hypersurfaces are endowed with a degenerate conformal structure. This is the reason that their…

Splitting theorems for hypersurfaces in Lorentzian manifolds

This paper looks at the splitting problem for globally hyperbolic spacetimes with timelike Ricci curvature bounded below containing a (spacelike, acausal, future causally complete) hypersurface with mean curvature bounded from above. For such spacetimes we show a splitting theorem under the assumption of either the existence of a ray of maximal length or a maximality condition on the volume of Lorentzian distance balls over the hypersurface. The proof of the first case follows work by Andersson, Galloway and Howard and uses their geometric maximum principle for level sets of the (Lorentzian) B…

Lightlike hypersurfaces on manifolds endowed with a conformal structure of Lorentzian signature

The authors study the geometry of lightlike hypersurfaces on manifolds $(M, c)$ endowed with a pseudoconformal structure $c = CO (n - 1, 1)$ of Lorentzian signature. Such hypersurfaces are of interest in general relativity since they can be models of different types of physical horizons. On a lightlike hypersurface, the authors consider the fibration of isotropic geodesics and investigate their singular points and singular submanifolds. They construct a conformally invariant normalization of a lightlike hypersurface intrinsically connected with its geometry and investigate affine connections i…

Comparison Theorems in Lorentzian Geometry and applications to spacelike hypersurfaces

In this paper we prove Hessian and Laplacian comparison theorems for the Lorentzian distance function in a spacetime with sectional (or Ricci) curvature bounded by a certain function by means of a comparison criterion for Riccati equations. Using these results, under suitable conditions, we are able to obtain some estimates on the higher order mean curvatures of spacelike hypersurfaces satisfying a Omori-Yau maximum principle for certain elliptic operators.

Remarks on screen integrable null hypersurfaces in Lorentzian manifolds

In the present paper, we show that the geometry of a screen integrable null hypersurface can be generated from an isometric immersion of a leaf of its screen distribution into the ambient space. We prove, under certain geometric conditions, that such immersions are contained in semi-Euclidean spheres or hyperbolic spaces, and the underlying null hypersurfaces are necessarily umbilic and screen totally umbilic. Where necessary, examples have been given to illustrate the main ideas.

Para Blaschke isoparametric spacelike hypersurfaces in Lorentzian space forms

Let $M^n$ be an $n$-dimensional umbilic-free hypersurface in the $(n+1)$-dimensional Lorentzian space form $M^{n+1}_1(c)$. Three basic invariants of $M^n$ under the conformal transformation group of $M^{n+1}_1(c)$ are a $1$-form $C$, called conformal $1$-form, a symmetric $(0,2)$ tensor $B$, called conformal second fundamental form, and a symmetric $(0,2)$ tensor $A$, called Blaschke tensor. The so-called para-Blaschke tensor $D^λ=A+λB$, the linear combination of $A$ and $B$, is still a symmetric $(0,2)$ tensor. A spacelike hypersurface is called a para-Blaschke isoparametric spacelike hypersu…

Lorentzian Geodesic Flows and Interpolation between Hypersurfaces in Euclidean Spaces

We consider geodesic flows between hypersurfaces in $\R^n$. However, rather than consider using geodesics in $\R^n$, which are straight lines, we consider an induced flow using geodesics between the tangent spaces of the hypersurfaces viewed as affine hyperplanes. For naturality, we want the geodesic flow to be invariant under rigid transformations and homotheties. Consequently, we do not use the dual projective space, as the geodesic flow in this space is not preserved under translations. Instead we give an alternate approach using a Lorentzian space, which is semi-Riemannian with a metric of…

Prescribed $k$-symmetric curvature hypersurfaces in de Sitter space

We prove existence of compact spacelike hypersurfaces with prescribed k - curvature in de Sitter space, where the prescription function depends on both space and the tilt function.

Lipschitz Continuous Hypersurfaces with Prescribed Curvature and Asymptotic Boundary in Hyperbolic Space

We prove the existence of a complete locally Lipschitz continuous hypersurface in weak sense with prescribed Weingarten curvature and asymptotic boundary at infinity in hyperbolic space under certain assumptions.

Closed hypersurfaces of prescribed mean curvature in locally conformally flat Riemannian manifolds

We prove the existence of smooth closed hypersurfaces of prescribed mean curvature homeomorphic to $S^n$ for small $n, n\le6$, provided there are barriers.

非紧流形中预定平均曲率超曲面的极小-极大构造

Min-max construction of prescribed mean curvature hypersurfaces in noncompact manifolds

该研究建立了非紧流形中预定平均曲率超曲面的极小-极大理论，适用于紧集外不变号的预定函数，并借此证明了两类超曲面的新存在性结果。

Volume preserving curvature flows in Lorentzian manifolds

Let N be a (n+1)-dimensional globally hyperbolic Lorentzian manifold with a compact Cauchy hypersurface. We consider curvature flows in N with different curvature functions F (including the mean curvature, the gauss curvature and the second elementary symmetric polynomial) and a volume preserving term. Under suitable assumptions we prove the long time existence of the flow and the exponential convergence of the corresponding graphs in the $C^\infty$-topology to a hypersurface of constant F-curvature. Furthermore we examine stability properties and foliations of constant F-curvature hypersurfac…

Stable maximal hypersurfaces in Lorentzian spacetimes

We study the geometry of stable maximal hypersurfaces in a variety of spacetimes satisfying various physically relevant curvature assumptions, for instance the Timelike Convergence Condition (TCC). We characterize stability when the target space has constant sectional curvature as well as give sufficient conditions on the geometry of the ambient spacetime (e.g., the validity of TCC) to ensure stability. Some rigidity results and height estimates are also proven in GRW spacetimes. In the last part of the paper we consider $k$-stability of spacelike hypersurfaces, a concept related to mean curva…

Convex Hypersurfaces with Prescribed Scalar Curvature and Asymptotic Boundary in Hyperbolic Space

The existence of a smooth complete strictly locally convex hypersurface with prescribed scalar curvature and asymptotic boundary at infinity in $\mathbb{H}^{3}$ is proved under the assumption that there exists a strictly locally convex subsolution.

PDE and hypersurfaces with prescribed mean curvature

These are lecture notes for the mini-course \textit{PDE and hypersurfaces with prescribed mean curvature} held in Federal University of São Carlos at the Workshop on Submanifold Theory and Geometric Analysis, August 05 -- 09, 2019. The aim of these notes is to introduce to the geometers useful tools from the \textit{Theory of partial differential equations} which are used in order to obtain hypersurfaces with prescribed mean curvature. For instance, graphs with prescribed mean curvature can be obtained by solving the Dirichlet problem for a particular quasilinear elliptic partial differential …

Existence of hypersurfaces with prescribed mean curvature I - Generic min-max

We prove that, for a generic set of smooth prescription functions $h$ on a closed ambient manifold, there always exists a nontrivial, smooth, closed hypersurface of prescribed mean curvature $h$. The solution is either an embedded minimal hypersurface with integer multiplicity, or a non-minimal almost embedded hypersurface of multiplicity one. More precisely, we show that our previous min-max theory, developed for constant mean curvature hypersurfaces, can be extended to construct min-max prescribed mean curvature hypersurfaces for certain classes of prescription function, including smooth Mor…

Starshaped locally convex hypersurfaces with prescribed curvature and boundary

In this paper we find strictly locally convex hypersurfaces in $\mathbb{R}^{n+1}$ with prescribed curvature and boundary. The main result is that if the given data admits a strictly locally convex radial graph as a subsolution, we can find a radial graph realizing the prescribed curvature and boundary. As an application we show any smooth domain on the boundary of a compact strictly convex body can be deformed to a smooth hypersurface with the same boundary (inside the convex body) and realizing any prescribed curvature function smaller than the curvature of the body.

Induced Riemannian structures on null hypersurfaces

Given a null hypersurface $L$ of a Lorentzian manifold, we construct a Riemannian metric $\widetilde{g}$ on it from a fixed transverse vector field $ζ$. We study the relationship between the ambient Lorentzian manifold, the Riemannian manifold $(L,\widetilde{g})$ and the vector field $ζ$. As an application, we prove some new results on null hypersurfaces, as well as known ones, using Riemannian techniques.

由环境函数规定平均曲率的毛细超曲面的紧致性

Compactness of capillary hypersurfaces with mean curvature prescribed by ambient functions

本文证明了由环境函数规定平均曲率的毛细超曲面的紧致性定理，推广了Schätzle和Bellettini的结果，并扩展了曲率varifold定义至有向积分varifold，同时讨论了边界平均曲率规定情形。

Geometric barriers for the existence of hypersurfaces with prescribed curvatures in $M^n\times R$

We show the existence of a deformation process of hypersurfaces from a product space $M_1\times R$ into another product space $M_2\times R$ such that the relation of the principal curvatures of the deformed hypersurfaces can be controlled in terms of the sectional curvatures or Ricci curvatures of $M_1$ and $M_2$. In this way, we obtain barriers which are used for proving existence or non existence of hypersurfaces with prescribed curvatures in a general product space $M\times R$.

Invariant hypersurfaces with linear prescribed mean curvature

Our aim is to study invariant hypersurfaces immersed in the Euclidean space $\mathbb{R}^{n+1}$, whose mean curvature is given as a linear function in the unit sphere $\mathbb{S}^n$ depending on its Gauss map. These hypersurfaces are closely related with the theory of manifolds with density, since their weighted mean curvature in the sense of Gromov is constant. In this paper we obtain explicit parametrizations of constant curvature hypersurfaces, and also give a classification of rotationally invariant hypersurfaces.

On the global existence of generalized rotational hypersurfaces with prescribed mean curvature in the Euclidean spaces. I

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 constant mean curvautre. Next, we prove the same kind of theorem for generalized rotational hypersurfaces of O(l+1) x O(m+1)-type. The key lemmas in this paper show the existence of solutions for singular initial value problems which arise from the analysis of ordinary differential equations of generating curves of those hypersurfaces.

Constant mean curvature spacelike hypersurfaces in Lorentzian warped products and Calabi-Bernstein type problems

In this paper we provide several uniqueness and non-existence results for complete parabolic constant mean curvature spacelike hypersurfaces in Lorentzian warped products under appropriate geometric assumptions. As a consequence of this parametric study, we obtain very general uniqueness and non-existence results for a large family of uniformly elliptic EDP's, so solving the Calabi-Bernstein problem in a wide family of spacetimes.

On compact hypersurfaces in a Riemannian vector bundle with prescribed vertical Gaussian curvature

Let M be a compact Riemannian manifold and E a Riemannian vector bundle on M. We look for hypersurfaces of E with a prescribed vertical Gaussian curvature. In trying to solve this problem fibre-wise, we loose the regularity of the resulting solution. To unsure the smoothness of the solution, we construct it as a radial graph over the unit sphere subbundle of E and prove its existence by solving in this one a nonlinear partial differential equation of Monge-Ampère type.

Nonpositively curved manifolds containing a prescribed nonpositively curved hypersurface

We use pinched smooth hyperbolization to show that every closed, nonpositively curved $n$-dimensional manifold $M$ can be embedded as a totally geodesic submanifold of a closed, nonpositively curved $(n+1)$-dimensional manifold $\hat{M}$ of geometric rank one.

洛伦兹流形中非紧超曲面的预定平均曲率流

Prescribed mean curvature flow for noncompact hypersurfaces in Lorentz manifolds

本文研究洛伦兹流形中从完备非紧类空超曲面出发的预定平均曲率流，给出短时间存在的充分条件，并讨论长时间存在性与收敛性，进而应用于闵可夫斯基时空和施瓦西时空未来零无穷远附近的相关问题。

黎曼与洛伦兹 Killing 淹没中预定平均曲率图的二元性

A duality for prescribed mean curvature graphs in Riemannian and Lorentzian Killing submersions

本文针对黎曼与洛伦兹 Killing 淹没中的类空图建立共形二元性，交换平均曲率与丛曲率并互逆 Killing 长度，由此得到洛伦兹-闵可夫斯基空间中预定平均曲率完整图的存在性及与临界平均曲率相关的存在与不存在条件。

具有指定高斯像的Hessian曲率超曲面

Hessian curvature hypersurfaces with prescribed Gauss image

本文研究指定高斯像的Hessian曲率超曲面问题，通过利用超曲面正交不变性的新型$C^2$边界估计方法，证明了满足指定k-Hessian曲率与高斯像条件的严格凸图超曲面的存在性。

与曲率形成向量场相关的规定角度超曲面研究

Prescribed Angle Surfaces Associated with Torse-Forming Vector Fields in Riemannian Manifolds

本文研究了与曲率形成向量场相关的规定角度超曲面，分析了其内在和外在曲率，并在特定条件下对这些超曲面进行了分类。

具有给定光学几何的流形的Levi-Civita联络

The Levi-Civita connections of manifolds with prescribed optical geometries

本文针对具有Kähler-Sasaki型光学几何的Lorentzian流形，用适配标架显式推导了Levi-Civita联络的Christoffel符号，并指出其在几何不变量确定和曲率约束求解中的应用。

Volume Comparison for Hypersurfaces in Lorentzian Manifolds and Singularity Theorems

We develop area and volume comparison theorems for the evolution of spacelike, acausal, causally complete hypersurfaces in Lorentzian manifolds, where one has a lower bound on the Ricci tensor along timelike curves, and an upper bound on the mean curvature of the hypersurface. Using these results, we give a new proof of Hawking's singularity theorem.

Geometric analysis of Lorentzian distance function on spacelike hypersurfaces

Some analysis on the Lorentzian distance in a spacetime with controlled sectional (or Ricci) curvatures is done. In particular, we focus on the study of the restriction of such distance to a spacelike hypersurface satisfying the Omori-Yau maximum principle. As a consequence, and under appropriate hypotheses on the (sectional or Ricci) curvatures of the ambient spacetime, we obtain sharp estimates for the mean curvature of those hypersurfaces. Moreover, we also give a suficient condition for its hyperbolicity.

The scalar curvature flow in Lorentzian manifolds

We prove the existence of closed hypersurfaces of prescribed scalar curvature in globally hyperbolic Lorentzian manifolds provided there are barriers.

Starshaped compact hypersurfaces with prescribed m-th mean curvature in hyperbolic space

We study the existence of starshaped compact hypersurfaces with prescribed m-th mean curvature in hyperbolic space.

The Dirichlet problem for prescribed curvature equations of $p$-convex hypersurfaces

In this paper, we study the Dirichlet problem for $p$-convex hypersurfaces with prescribed curvature. We prove that there exists a graphic hypersurface satisfying the prescribed curvature equation with homogeneous boundary condition. An interior curvature estimate is also obtained.

Hypersurfaces of prescribed null expansion

We study hypersurfaces with prescribed null expansion in an initial data set. We propose a notion of stability and prove a topology theorem. Eichmair's Perron approach toward the existence of marginally outer trapped surface adapts to the settings of hypersurfaces with prescribed null expansion with only minor modifications.

Higher order mean curvature estimates for bounded complete hypersurfaces

We obtain sharp estimates involving the mean curvatures of higher order of a complete bounded hypersurface immersed in a complete Riemannian manifold. Similar results are also given for complete spacelike hypersurfaces in Lorentzian ambient spaces.

Curvature estimates for $p$-convex hypersurfaces of prescribed curvature

In this paper, we establish the curvature estimates for $p$-convex hypersurfaces in $\mathbb{R}^{n+1}$ of prescribed curvature with $p\geq \frac{n}{2}$. The existence of a star-shaped hypersurface of prescribed curvature is obtained. We also prove a type of interior $C^2$ estimates for solutions to the Dirichlet problem of the corresponding equation.

双曲空间中具有指定无穷远渐近边界的常数量曲率超曲面

Hypersurfaces of constant scalar curvature in hyperbolic space with prescribed asymptotic boundary at infinity

本文推广双曲空间经典渐近普拉托问题，通过构造常数量曲率图极限并引入新技术建立二阶先验估计，证明所有可能曲率值下存在具指定无穷远渐近边界的光滑完备常数量曲率超曲面。

凸毛细超曲面的 prescribed $L_{p}$ 曲率问题

Prescribed $L_{p}$ curvature problem for convex capillary hypersurface

本文研究了欧几里得半空间中凸毛细超曲面的 prescribed $L_p$ 曲率问题，通过转化问题为 Hessian 商类型方程，证明了解的存在性和唯一性，并应用该方法解决了毛细 $L_p$ Christoffel-Minkowski 问题及相关特征值问题。

Hypersurfaces of Prescribed Gauss Curvature in Exterior Domains

We prove an existence theorem for convex hypersurfaces of prescribed Gauss curvature in the complement of a compact set in Euclidean space which are close to a cone.

Dirac operators on lightlike hypersurfaces

In this study, we obtain a spinorial Gauss formula for a lightlike hypersurface in Lorentzian manifold with 4-dimension. Then, we take into account the changes caused by degenerate metric on hypersurface and investigate Dirac operator for lightlike hypersurface. Later, we establish the relation between Dirac operators and Riemannian curvatures of manifold and hypersurface.

Entire spacelike hypersurfaces of prescribed Gauss curvature in Minkowski space

We are concerned with spacelike convex hypersurfaces of positive constant (K-hypersurfaces) or prescribed Gauss curvature in Minkowski space. Our main purpose is to study entire solutions as well as the Dirichlet problem in bounded domains of the related Monge-Ampere equation.

Lightlike hypersurfaces along spacelike submanifolds in anti-de Sitter space

Anti-de Sitter space is the Lorentzian space form with negative curvature. In this paper we consider lightlike hypersurfaces along spacelike submanifolds in anti-de Sitter space with general codimension. In particular, we investigate the singularities of lightlike hypersurfaces as an application of the theory of Legendrian singularities.

Entire spacelike hypersurfaces of prescribed scalar curvature in Minkowski space

We prove existence and uniqueness of entire spacelike hypersurfaces in the Minkowski space with prescribed negative scalar curvature, and with given values at infinity which stay at a bounded distance of a lightcone.

具有预定平均曲率超曲面的渐近 Plateau 问题

Asymptotic Plateau problem for prescribed mean curvature hypersurfaces

本文证明了在满足严格凸性条件且截面曲率具有负常数上界的 Cartan-Hadamard 流形中，具有预定平均曲率超曲面的渐近 Plateau 问题解的存在性，并在低维情形下得到了多重性结果。

On the global existence of generalized rotational hypersurfaces with prescribed mean curvature in the Euclidean spaces, II

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 existence result is shown for any type.

具有指定梯度像的常平均曲率超曲面

The constant mean curvature hypersurfaces with prescribed gradient image

该文研究具指定梯度像的常平均曲率超曲面的存在性，在ℝⁿ中一致凸有界光滑域的条件下，证明常平均曲率方程第二边值问题存在唯一凸解。

Hypersurfaces in non-flat Lorentzian space forms satisfying $L_kψ=Aψ+b$

We study hypersurfaces either in the De Sitter space $§_1^{n+1}\subset\R_1^{n+2}$ or in the anti De Sitter space $\H_1^{n+1}\subset\R_2^{n+2}$ whose position vector $ψ$ satisfies the condition $L_kψ=Aψ+b$, where $L_k$ is the linearized operator of the $(k+1)$-th mean curvature of the hypersurface, for a fixed $k=0,...,n-1$, $A$ is an $(n+2)\times(n+2)$ constant matrix and $b$ is a constant vector in the corresponding pseudo-Euclidean space. For every $k$, we prove that when $A$ is self-adjoint and $b=0$, the only hypersurfaces satisfying that condition are hypersurfaces with zero $(k+1)$-th me…

A note on starshaped compact hypersurfaces with a prescribed scalar curvature in space forms

In [7], Guan, Ren and Wang obtained a $C^2$ a priori estimate for admissible 2-convex hypersurfaces satisfying the Weingarten curvature equation $σ_2(κ(X))=f(X, ν(X)).$ In this note, we give a simpler proof of this result, and extend it to space forms.