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An algorithm of finding planar surfaces in three-manifolds
E. A. Sbrodova Chelyabinsk State University
Аннотация:
This paper is devoted to the question: does there exist an algorithm to decide whether or not a given
$3$-manifold contains a proper essential planar surface? By a
planar surface we mean a punctured disc.
There is an algorithm, due to W. Jaco, to decide whether a
$3$-manifold admits a proper essential disc, i.e., whether it is boundary reducible. A close result, an algorithm allow us to say whether a manifold contains a proper essential disc with a given boundary, was obtained by W. Haken in 60-th. In 1998 W. Jaco, H. Rubinstein and E. Sedgwick described an algorithm to decide whether or not a given linkmanifold contains a proper essential planar surface (a link-manifold is a compact orientable
$3$-manifold whose boundary consists of tori) [1]. We generalize this result to manifolds with arbitrary boundaries.
A
slope on the boundary of a
$3$-manifold
$M$ is the isotopy class of a finite set of disjoint simple closed curves
$\{\alpha_1,\dots,\alpha_n\}$ in
$\partial M$ which are nontrivial and pairwise nonparallel. We say that the boundary of a proper surface
$F$ has a slope
$\alpha=\{\alpha_1,\dots,\alpha_n\}$ if the boundary components of
$F$ are each parallel to one of the curves
$\alpha_1,\dots,\alpha_n$.
УДК:
515.16
MSC: 57M25 Поступила 15 октября 2005 г., опубликована
17 октября 2005 г.
Язык публикации: английский