Diffeomorphism classification of finite group actions on disks (Q799272)

Suppose a smooth G-manifold \((M^ k,\partial M^ k)\) is embedded in the n-disk \((D^ n,\partial D^ n)\). The reviewer studied the problem of extending this action from M to \(D^ n\) and the classification of such extensions [see Mem. Am. Math. Soc. 257 (1982; Zbl 0486.57015), Chapter VI, for a brief survey of the results in this direction]. The author proposes an alternative condition for the tangential data of \(M^ k\) when \(k=n\) and the action on \((D^ n-M^ n)\) is required to be free. He uses the \((\pi -\pi)-\)theorem of Wall to construct the extension and to classify the extensions, obtaining similar results to some of the results of \textit{W. Browder} and the reviewer (to appear in Trans. Am. Math. Soc., see op. cit.) which used thickening techniques.