In this paper, we classify $3$-dimensional complete self-shrinkers in Euclidean space $\mathbb R^{4}$ with constant squared norm of the second fundamental form $S$ and constant $f_{4}$.
The purpose of this paper is to study complete self-shrinkers of mean curvature flow in Euclidean spaces. In the paper, we give a complete classification for 2-dimensional complete Lagrangian self-shrinkers in Euclidean space $\mathbb R^4$ with constant squared norm of the second fundamental form.
Complete self-shrinkers confined into some regions of the space
我们研究了完备非紧有界自收缩曲面的几何性质,得到了使这些超曲面成为紧的自然限制条件。此外,我们观察到,在一定程度上,完全的自收缩相交的超平面通过原点。当这样的交集是紧凑的,我们推导出光谱信息的自然漂移拉普拉斯相关的自收缩。这些结果对于验证H. D. Cao关于完全自收缩体的多项式体积增长。对于自收缩体被限制在圆柱形制品中的情况,给出了有限强最大值原理。
In this paper, we study complete self-shrinkers in Euclidean space and prove that an $n$-dimensional complete self-shrinker in Euclidean space $\mathbb{R}^{n+1}$ is isometric to either $\mathbb{R}^{n}$, $S^{n}(\sqrt{n})$, or $S^k (\sqrt{k})\times\mathbb{R}^{n-k}$, $1\leq k\leq n-1$, if the squared norm $S$ of the second fundamental form, $f_3$ are constant and $S$ satisfies $S<1.83379$. We should remark that the condition of polynomial volume growth is not assumed.
In this paper, we completely classify $3$-dimensional complete self-shrinkers with constant norm $S$ of the second fundamental form and constant $f_{3}$ in Euclidean space $\mathbb R^{4}$, where $h_{ij}$ are components of the second fundamental form, $S=\sum_{i,j}h^{2}_{ij}$ and $f_{3}=\sum_{i,j,k}h_{ij}h_{jk}h_{ki}$.
In this paper, we present a sufficient condition for finite Morse index of complete properly self-shrinkers. We prove that a complete properly embedded self-shrinker in $\mathbb{R}^{n+1}$ with finite asymptotically conical ends or asymptotically cylindrical ends must have finite Morse index. Moreover, as an application of this result, we show that a complete properly embedded self-shrinker in $\mathbb{R}^3$ with finite genus has finite Morse index.
In this paper we apply a geometric covering method to study the number of ends on shrinkers. On one hand, we prove that the number of ends on any complete non-compact shrinker is at most polynomial growth with fixed degree. On the other hand, we prove that any complete non-compact shrinker with certain volume comparison condition has finitely many ends. Some special cases of shrinkers are also discussed.
We show that any $4$-dimensional complete self-shrinker in $\mathbb{R}^{5}$ with constant squared norm $S$ of the second fundamental form, $f_{3}=0$ and constant $f_{4}$ is isometric to $\mathbb{R}^{4}$, where $h_{ij}$ are components of the second fundamental form, $S=\sum h_{ij}^{2}$, $f_{3}=\sum h_{ij}h_{jk}h_{ki}$ and $f_{4}=\sum h_{ij}h_{jk}h_{kl}h_{li}$. As an application, we obtain a classification result.
Rigidity theorems for complete Legendrian self-shrinkers
Shanghai Institute for Mathematics and Interdisciplinary Sciences(上海数学与交叉学科研究院);School of Mathematics and Statistics Wuhan University(武汉大学数学与统计学院);School of Mathematical Sciences Chongqing University of Technology(重庆理工大学数学科学学院)
Self-shrinkers of the mean curvature flow in arbitrary codimension
对于维数大于1的超曲面,Huisken证明了具有正标量中曲率的中曲率流的紧致自收缩体是球面。我们将证明以下扩展:一个紧致的自相似的解决方案在任意余维和维数大于1是球形的,即包含在一个球,当且仅当中曲率向量\be H \ee是非零的和主法线\be ν \ee是平行的正常丛。我们还给出了这类完全非紧自收缩子的一个分类。
In this paper, we firstly verify that if $M$ is a complete self-shrinker with polynomial volume growth in $\mathbb{R}^{n+1}$, and if the squared norm of the second fundamental form of $M$ satisfies $0\leq|A|^2-1\leq\frac{1}{18}$, then $|A|^2\equiv1$ and $M$ is a round sphere or a cylinder. More generally, let $M$ be a complete $λ$-hypersurface with polynomial volume growth in $\mathbb{R}^{n+1}$ with $λ\neq0$. Then we prove that there exists an positive constant $γ$, such that if $|λ|\leqγ$ and the squared norm of the second fundamental form of $M$ satisfies $0\leq|A|^2-β_λ\leq\frac{1}{18}$, th…
We construct Gaussian Harmonic forms of finite Gaussian weighted $L^2$-norm on non-compact surfaces that detect each asymptotically conical end. As an application we prove an extension of the index estimates of self-shrinkers in $[11]$ under the existence of such ends. We show that the Morse index of a self-shrinker is greater or equal to $\frac{2g+r-1}{3}$, where $r$ is the number of asymptotically conical ends.
Eigenvalue Estimates for Schrödinger Operators on Ricci Shrinkers
Instituto de Matemática e Estatística, Universidade Federal Fluminense(弗鲁米嫩塞联邦大学数学与统计研究所);Departamento de Matemática, Universidade Federal de Sergipe(塞尔希培联邦大学数学系);Universidade Federal do Amazonas Instituto de Ciências Exatas(亚马孙联邦大学理学院)
Rigidity and Curvature Estimates for Graphical Self-shrinkers
自收缩器是在中曲率流动下相似收缩的超曲面;这些孤子模拟了流动的奇异性。目前已知一个整自缩图必是一个超平面。在本文中,我们表明,超平面是刚性的,在更强的意义上,即:对于$2 \leq n \leq 6$,任何光滑,完整的自收缩$Σ^n\subset\mathbf{R}^{n+1}$,这是图形内的一个大的,但紧凑的,必须是一个超平面。事实上,这种刚性存在于更大的一类几乎稳定的自收缩体中。本文的一个关键组成部分是采购的线性曲率估计几乎稳定的收缩,这是负责对$n$的限制这一步。我们的方法也产生一致的曲率界的平移孤子的中曲率流。
We study the Morse index of self-shrinkers for the mean curvature flow and, more generally, of $f$-minimal hypersurfaces in a weighted Euclidean space endowed with a convex weight. When the hypersurface is compact, we show that the index is bounded from below by an affine function of its first Betti number. When the first Betti number is large, this improves index estimates known in literature. In the complete non-compact case, the lower bound is in terms of the dimension of the space of weighted square summable $f$-harmonic $1$-forms; in particular, in dimension $2$, the procedure gives an in…
As is well known, self-similar solutions to the mean curvature flow, including self-shrinkers, translating solitons and self-expanders, arise naturally in the singularity analysis of the mean curvature flow. Recently, Guo \cite{Guo} proved that $n$-dimensional compact self-shrinkers in $\mathbb{R}^{n+1}$ with scalar curvature bounded from above or below by some constant are isometric to the round sphere $\mathbb{S}^n(\sqrt{n})$, which implies that $n$-dimensional compact self-shrinkers in $\mathbb{R}^{n+1}$ with constant scalar curvature are isometric to the round sphere $\mathbb{S}^n(\sqrt{n}…