共形空间${\mathbb Q}^n_s$中的正则Blaschke拟全脐子流形

[Nie C X,Wu C X,Regular submanifolds in the conformal space Q_p~n,ChinAnn Math,2012,33B(5):695-714]中研究了共形空间Q_s~n中的正则子流形,并引入了共形空间Q_s~n中的子流形理论.本文作者将分类共形空间Q_s~n中的Blaschke拟全脐子流形,证明伪Riemann空间形式中具有常数量曲率和平行的平均曲率向量场的正则子流形是共形空间中的Blaschke拟全脐子流形;反之,共形空间中的Blaschke拟全脐子流形共形等价于伪Riemann空间形式中具有常数量曲率和平行的平均曲率向量场的正则子流形.这一结论可看作是共形空间Q_s~n中共形迷向子流形分类定理的推广.     

S~4中具有调和共形高斯映照的超曲面

设x:M~n→S~(n+1)是球面S~(n+1)中的一个定向超曲面,其共形高斯映照G=(H,Hx+en+.1):M~n→R_1S~(n+3)是M(o|¨)bius变换群下的一个不变量,其中H,e(n+1)+1分别是超曲面x的平均曲率和单位法向量场.本文研究了S~4中具有调和共形高斯映照的超曲面,分类了具有调和共形高斯映照和常M(o|¨)bius数量曲率的超曲面,给出了具有调和共形高斯映照但不是Willmore超曲面的例子.     

高斯曲率估计与常数平均曲率超曲面的稳定性

本文利用活动标架法及Ｌａｐｌａｃｉａｎ特征值方法研究了常数平均曲率超曲面的稳定性．给出了三维拟常曲率流形中具有常数平均曲率超曲面的共形度量的高斯曲率之上界估计．证明了三维拟常曲率流形中具有常数平均曲率超曲面上一个单连通有界区域为稳定的充分条件．     

双曲空间中的共形平坦级小超曲面

本文证明了双曲空间中共形平坦极小超曲面必为旋转超曲面或由一些旋转超曲面片用全测地超曲面片粘合而成，将这结果与王新民及许志才的一个已发表定理相组合，推广了Ｂｌａｉｒ关于推广悬链面的一个定理。     

四维洛伦兹空间中形状算子不可对角化且有两个不同主曲率类时共形齐性超曲面的分类

如果对任意两点p,q∈M₁³,都存在洛伦兹空间R₁⁴中的一个共形变换σ,使得σ(x(p))=x(q),并且σ(x(M₁³))=x(M₁³),则称x(M₁³)为共形齐性超曲面.在本文中我们主要研究形状算子不可对角化且具有2个不同主曲率的类时共形齐性超曲面x:M₁³→R₁⁴.通过定义共形不变度量g_c,典则提升Y,共形切标架{E_i}和典则法标架ξ,我们给出了这类超曲面的一个完备共形不变量系统{E₁,E₂,E₃}.接下来利用可积性条件构造出了这类超曲面的显式表达式及相应的共形变换子群,从而得到了对这类超曲面的分类定理.     

${R}_{0}$代数中的滤子格

Abstract In the present paper, some basic properties of MP filters of Ro algebra M are investigated. It is proved that（FMP（M）,包含,′∧^-∨^-,{1},M）is a bounded distributive lattice by introducing the negation operator ′, the meet operator ∧^-, the join operator ∨^- and the implicati on operator → on the set FMP（M） of all MP filters of M. Moreover, some conditions under which （FMP（M）,包含,′∨^-,→{1},M）is an Ro algebra are given. And the relationship between prime elements of FMP （M） and prime filters of M is studied. Finally, some equivalent characterizations of prime elements of .FMP （M） are obtained.     

共形空间中有两个共形主曲率的共形等参超曲面

研究了共形空间中正则超曲面的共形几何,并在共形等价意义下对有两个共形主曲率的共形等参超曲面作了分类.     

de Sitter空间S1m+1中具有平行Blaschke张量的正则类空超曲面

本文引入两个以de Sitter空间为模型的非齐性坐标来覆盖共形空间Q₁^m+1.利用球面S^m+1中超曲面的Möbius几何的方法,本文研究了Q₁^m+1中正则类空超曲面的共形几何.作为其结果,本文对所有具有平行Blaschke张量的正则类空超曲面进行了完全分类.     

两类N=2超共形代数上的超双导子和超交换映射

确定广义Topological N=2超共形代数和Twisted N=2超共形代数上的超斜对称双导子.证明在这两类超代数上的所有超双导子都是超双内导子.应用此结论,得到在广义Topological N=2超共形代数上的线性超交换映射是非标准的,而Twisted N=2超共形代数上的线性超交换映射是标准的.     

第二大特征值小于$\frac{\sqrt{5}-1}{2}$的平面图

若能将图$G$画在一个平面上,使得任何两条边仅在顶点处相交,则称$G$是平面图.本文刻画了第二大特征值小于$\frac{\sqrt{5}-1}{2}$的所有无孤立点的平面图.     

On Holomorphic Automorphisms of a Class of Non-homogeneous Rigid Hypersurfaces in C^N＋1

The author determines the real-analytic infinitesimal CR automorphisms of a class of non-homogeneous rigid hypersurfaces in C^N＋1 near the origin, and the connected component containing the identity transformation of all locally holomorphic automorphisms of these hypersurfaces near the origin.     

Rearrangement Free Method for Hardy-Littlewood-Sobolev Inequalities on $\mathbb{S}^n$

For conformal Hardy-Littlewood-Sobolev(HLS) inequalities [22] and reversed conformal HLS inequalities [8] on $\mathbb{S}^n,$ a new proof is given for the attainability of their sharp constants. Classical methods used in [22] and [8] depends on rearrangement inequalities. Here, we use the subcritical approach to construct the extremal sequence and circumvent the blow-up phenomenon by renormalization method. The merit of the method is that it does not rely on rearrangement inequalities.     

A variational characterization for $\sigma_{n/2}$

We present here a conformal variational characterization in dimension n = 2k of the equation , where A is the Schouten tensor. Using the fully nonlinear parabolic flow introduced in [3], we apply this characterization to the global minimization of the functional.Received: 31 March 2003, Accepted: 10 July 2003, Published online: 25 February 2004Research supported in part by an NSF Postdoctoral Fellowship.     

On the tangential Cauchy‐Fueter operators on nondegenerate quadratic hypersurfaces in \documentclass{article}\usepackage{amssymb}\begin{document}\pagestyle{empty}${\mathbb {H}^2}$\end{document}

On quadratic hypersurfaces in $\mathbb {H}^2$, we find the explicit forms of tangential Cauchy‐Fueter operators and associated tangential Laplacians □_b. Then by using the Fourier transformation on the associated nilpotent Lie groups of step two, we construct the relative fundamental solutions to the tangential Laplacians and Szegö kernels on the nondegenerate quadratic hypersurfaces. It is different from the complex case that the quaternionic tangential structures on the nondegenerate quadratic hypersurfaces in $\mathbb {H}^2$ cannot be reduced to one standard model and the non‐homogeneous tangential Cauchy‐Fueter equations are solvable even in many convex cases.     

WEIERSTRASS REPRESENTATION FORSURFACES WITH PRESCRIBED NORMALGAUSS MAP AND GAUSS CURVATURE IN H~3

The author obtains a Weierstrass representation for surfaces with prescribed normal Gauss map and Gauss curvature in H3. A differential equation about the hyperbolic Gauss map is also obtained, which characterizes the relation among the hyperbolic Gauss map, the normal Gauss map and Gauss curvature. The author discusses the harmonicity of the normal Gauss map and the hyperbolic Gauss map from surface with constant Gauss curvature in H3 to S2 with certain altered conformal metric. Finally, the author considers the surface whose normal Gauss map is conformal and derives a completely nonlinear differential equation of second order which graph must satisfy.     

Period functions for $ {\mathcal{C}^0} $- and $ {\mathcal{C}^1} $-flows

Let F:M ×\mathbbR ? M {\mathbf{F}}:M \times \mathbb{R} \to M be a continuous flow on a manifold M, let V ⊂ M be an open subset, and let x:V ? \mathbbR \xi :V \to \mathbb{R} be a continuous function. We say that ξ is a period function if F(x, ξ(x)) = x for all x ∈ V. Recently, for any open connected subset V ⊂ M; the author has described the structure of the set P(V) of all period functions on V. Assume that F is topologically conjugate to some C¹ {\mathcal{C}^1} -flow. It is shown in this paper that, in this case, the period functions of F satisfy some additional conditions that, generally speaking, are not satisfied for general continuous flows.     

关于同伦元素 $\alpha_{1}\beta_{1}\beta_{2}\gamma_{s}$

设 $p\geq 7$ 为任意奇素数. 证明了当 $3\leq s 相似文献   

Boundaries of Holomorphic 1-Chains Within Holomorphic Line Bundles over $\mathbb{CP}^{1}$

We show that boundaries of holomorphic 1-chains within holomorphic line bundles of \mathbbCP¹\mathbb{CP}^{1} can be characterized using a single generating function of Wermer moments. In the case of negative line bundles, a rationality condition on the generating function plus the vanishing moment condition together form an equivalent condition for bounding. We provide some examples which reveal that the vanishing moment condition is not sufficient by itself. These examples also can be used to demonstrate one point of caution about the use of birational maps in this topic.     

The complete hyper-surfaces with zero scalar curvature in \mathbb{R }^{n+1}

Let $M^n$ be a complete and noncompact hyper-surface immersed in $R^{n+1}$ . We should show that if $M$ is of finite total curvature and Ricci flat, then $M$ turns out to be a hyperplane. Meanwhile, the hyper-surfaces with the vanishing scalar curvature is also considered in this paper. It can be shown that if the total curvature is sufficiently small, then by refined Kato’s inequality, conformal flatness and flatness are equivalent in some sense. And those results should be compared with Hartman and Nirenberg’s similar results with flat curvature assumption.     

Refinement of the Relations between Mixed Smoothness Moduli in $ L_{1} $ and $ L_{q} $ Metrics

Siberian Mathematical Journal - We refine some relations between the mixed smoothness moduli of fractional orders which are considered in the  $ L_{1} $ and  $ L_{q} $ metrics.