منابع مشابه
Manifolds with non-stable fundamental groups at infinity
The notion of an open collar is generalized to that of a pseudo-collar. Important properties and examples are discussed. The main result gives conditions which guarantee the existence of a pseudo-collar structure on the end of an open n–manifold (n ≥ 7). This paper may be viewed as a generalization of Siebenmann’s famous collaring theorem to open manifolds with non-stable fundamental group syst...
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T T T T T T T T T T T T T T T Abstract In this paper we continue an earlier study of ends non-compact manifolds. The over-arching goal is to investigate and obtain generalizations of Siebenmann's famous collaring theorem that may be applied to manifolds having non-stable fundamental group systems at infinity. In this paper we show that, for mani-folds with compact boundary, the condition of inw...
متن کاملManifolds with non-stable fundamental groups at infinity, III
This is the third in a series of papers aimed at generalizing Siebenmann’s famous PhD thesis [13] so that the results apply to manifolds with nonstable fundamental groups at infinity. Siebenmann’s work provides necessary and sufficient conditions for an open manifold of dimension ≥ 6 to contain an open collar neighborhood of infinity, ie, a manifold neighborhood of infinity N such that N ≈ ∂N ×...
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We study the Dehn function at infinity in the mapping class group, finding a polynomial upper bound of degree four. This is the same upper bound that holds for arbitrary right-angled Artin groups. Dehn functions quantify simple connectivity. That is, in a simply-connected space, every closed curve is the boundary of some disk; the Dehn function measures the area required to fill the curves of a...
متن کاملFree group automorphisms with many fixed points at infinity
A concrete family of automorphisms αn of the free group Fn is exhibited, for any n ≥ 3, and the following properties are proved: αn is irreducible with irreducible powers, has trivial fixed subgroup, and has 2n− 1 attractive as well as 2n repelling fixed points at ∂Fn . As a consequence of a recent result of V Guirardel there can not be more fixed points on ∂Fn , so that this family provides th...
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ژورنال
عنوان ژورنال: Topology
سال: 1996
ISSN: 0040-9383
DOI: 10.1016/0040-9383(95)00033-x