几乎交错纽结补中决定的不可压缩曲面

本文讨论了几乎交错纽结补中的不压缩，两两不可压缩曲面的性质．证明了，当Ｋ是素的几乎交错纽结时，若ＦＳ３－Ｋ是不可压缩、两两不可压缩曲面，则对于固定的边界分支数ｎ，曲面Ｆ的合痕类是有限的．     

纽结补中不可压缩且配对不可压缩曲面的性质

本文主要利用链环补空间中曲面拓扑图的性质来研究一类链环L(n,3)(n∈Z~+)补空间中处于标准位置的不可压缩且配对不可压缩曲面F的性质,进而得到曲面F的特征数.首先,根据纽结的性质,对一类链环L(n,3)进行研究,给出这类链环的分类,然后对于标准化后的链环L(n,3),如果F?S~3-L(n,3)为不可压缩且配对不可压缩曲面,则F为穿孔球面.     

交错纽结补中的不可压缩、两两不可压缩曲面

本文利用ｔｗｉｓｔ－ｃｒｏｓｓｉｎｇ ｎｕｍｂｅｒ讨论了交错纽结补中的不可压缩、两两不可压缩曲面的性质．设Ｋ是素的交错纽结，Ｆ?Ｓ^３－Ｋ是不可压缩、两两不可压缩曲面．如果Ｋ的ｔｗｉｓｔ－ｃｒｏｓｓｉｎｇ ｎｕｍｂｅｒ不超过５，则曲面Ｆ是ｐｕｎｃｔｕｒｅｄ ｓｐｈｅｒｅ．     

纽结补中的不可压缩分段不可压缩曲面

本文利用扭转交叉数（twist-erossing number)讨论扭结补中的不可压缩分段不可压缩曲面的性质,设K是一个排叉结（pretzel knot)或者是一个扭转交叉数少于6的有理纽结,如果F是S^3-K中的不可压缩分段不可压缩曲面,那么F是一个穿孔球面。     

简单拓扑图及几乎交错链环补中的闭曲面*

研究了在曲面拓扑图的每个球泡中最多有一个鞍点的情况下,拓扑图的简单性与曲面亏格的关系. 并利用正方形素方割的性质讨论了素、非分离几乎交错链环补空间中的闭、不可压缩、分段不可压缩曲 面的性质.     

Incompressible pairwise incompressible surfaces in link complements

The central subject of studying in this paper is incompressible pairwise incompressible surfaces in link complements. Let L be a non-split prime link and let F be an incompressible pairwise incompressible surface in S~3 - L. We discuss the properties that the surface F intersects with 2-spheres in S~3 - L. The intersection forms a topological graph consisting of a collection of circles and saddle-shaped discs. We introduce topological graphs and their moves (R-move and S~2-move), and define the characteristic number of the topological graph for F∩S~2±. The characteristic number is unchanged under the moves. In fact, the number is exactly the Euler Characteristic number of the surface when a graph satisfies some conditions. By these ways, we characterize the properties of incompressible pairwise incompressible surfaces in alternating (or almost alternating) link complements. We prove that the genus of the surface equals zero if the component number of F∩S~2+(or F∩S~2-) is less than five and the graph is simple for alternating or almost alternating links. Furthermore, one can prove that the genus of the surface is zero if #(F) ≤8.     

Incompressible surfaces in handlebodies and closed 3-manifolds of Heegaard genus 2

In this paper, we shall prove that for any integer 0$">, 1) a handlebody of genus 2 contains a separating incompressible surface of genus , 2) there exists a closed 3-manifold of Heegaard genus which contains a separating incompressible surface of genus .

     

Almost Alternating Diagrams and Fibered Links in S3

Let R be a Seifert surface obtained by applying Seifert's algorithmto a connected diagram D for a link L. In this paper, lettingD be almost alternating, we give a practical algorithm to determinewhether L is a fibered link and R is a fiber surface. We furthershow that L is a fibered link and R is a fiber surface for Lif and only if R is a Hopf plumbing, that is, a successive plumbingof a finite number of Hopf bands. It has been known for sometime that this is true if D is alternating, and we show thatit is not always true if D is 2-almost alternating. In the appendix,we partially answer C. Adams's open question concerning almostalternating diagrams. 2000 Mathematical Subject Classification:57M25.     

The Volume of Hyperbolic Alternating Link Complements

If a hyperbolic link has a prime alternating diagram D, thenwe show that the link complement's volume can be estimated directlyfrom D. We define a very elementary invariant of the diagramD, its twist number t(D), and show that the volume lies betweenv₃(t(D) – 2)/2 and v₃(10t(D) – 10), where v₃ isthe volume of a regular hyperbolic ideal 3-simplex. As a consequence,the set of all hyperbolic alternating and augmented alternatinglink complements is a closed subset of the space of all completefinite-volume hyperbolic 3-manifolds, in the geometric topology.2000 Mathematics Subject Classification 57M25, 57N10.     

The Existence of a Meridional Curve in Closed Incompressible Surfaces in Fully Alternating Link Complements

Menasco showed that a closed incompressible surface in the complement of a non-split prime alternating link in S³ contains a circle isotopic in the link complement to a meridian of the links.Based on this result,he was able to argue the hyperbolicity of non-split prime alternating links in S³.Adams et al.showed that if F ? S×Ⅰ L is an essential torus,then F contains a circle which is isotopic in S×Ⅰ L to a meridian of L.The author generalizes his result as follows:Let S be ...     

A Kind of Essential Surfaces in the Complements of Knots

In this paper, by the twist-crossing number of knots, we give an upper bound on the Euler characteristic of a kind of essential surfaces in the complements of alternating knots and almost alternating knots, which improves the estimation of the Euler characteristic of the essential surfaces with boundaries under certain conditions. Furthermore, we give the genus of the essential surfaces.     

Incompressible pairwise incompressible surfaces in almost alternating knot complements

In this paper, we deal with incompressible pairwise incompressible surfaces in almost alternating knot complements. We show that the genus of a surface in an almost alternating knot exterior equals zero if there are two, four or six boundary components in the surface.