Hostname: page-component-cb9f654ff-fg9bn Total loading time: 0 Render date: 2025-08-14T02:10:05.719Z Has data issue: false hasContentIssue false

Diffeomorphisms of some smooth metastably connected manifolds

Published online by Cambridge University Press:  24 October 2008

J. P. E. Hodgson
Affiliation:
University of Pennsylvania, Philadelphia 19104, U.S.A.
Rights & Permissions [Opens in a new window]

Extract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

Let Mm be a closed connected smooth manifold of dimension m, and set Pm = Mm – int Dm where Dm is a disc in M. In (4), Wall has the following exact sequence

where (M), (resp. (P)) is the Δ-set of diffeomorphisms of M (resp. P) as in(l), and [M/P] is the set of diffeomorphism classes of smooth manifolds obtained by glueing a disc to the boundary of P. In this paper we obtain some results on π0((M)) for particular M, and in the following sense: Using the techniques of (2), we can determine π0((P)), so the main portion of the paper is concerned with a discussion of the kernel of α. There is a map ω: π1((P)) → Γm+1, given by the obstruction to extending h∈π1((P)) to a concordance of the identity of M to itself, and it is clear that if this map is attached at the beginning of the sequence (*) we get exactness. We will obtain (for certain M) an alternative description of the image of α in terms of those homotopy spheres which can appear as the boundaries of thickenings.

Information

Type
Research Article
Copyright
Copyright © Cambridge Philosophical Society 1972

References

REFERENCES

(1)Hodgson, J. P. E.Obstructions to Concordance for Thickenings. Invent. Math. 5 (1968), 292396.CrossRefGoogle Scholar
(2)Hodgson, J. P. E.Automorphisms of metastably connected PL-manifolds. Proc. Cambridge Philos. Soc. 69 (1971), 75.CrossRefGoogle Scholar
(3)Milnor, J. W.Differentiable structures on spheres. Amer. J. Math. 81 (1959), 962972.CrossRefGoogle Scholar
(4)Wall, C. T. C.Classification Problems in Differential Topology II. Topology 2 (1963), 263272.CrossRefGoogle Scholar
(5)Wall, C. T. C.The action of Γ2n on (n – l)-connected 2n-manifolds. Proc. Amer. Math. Soc. 13 (1962), 943944.Google Scholar