Displaying similar documents to “Abelian subgroups of the Torelli group.”

Mapping class group of a handlebody

Bronisław Wajnryb (1998)

Fundamenta Mathematicae

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Let B be a 3-dimensional handlebody of genus g. Let ℳ be the group of the isotopy classes of orientation preserving homeomorphisms of B. We construct a 2-dimensional simplicial complex X, connected and simply-connected, on which ℳ acts by simplicial transformations and has only a finite number of orbits. From this action we derive an explicit finite presentation of ℳ.

A combinatorial approach to singularities of normal surfaces

Sandro Manfredini (2003)

Annali della Scuola Normale Superiore di Pisa - Classe di Scienze

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In this paper we study generic coverings of ℂ 2 branched over a curve s.t. the total space is a normal analytic surface, in terms of a graph representing the monodromy of the covering, called monodromy graph. A complete description of the monodromy graphs and of the local fundamental groups is found in case the branch curve is { x n = y m } (with n ≤ m ) and the degree of the cover is equal to n or n - 1 .