Consider G = Z 2 2 as the group generated by two commuting involutions, and let : G × M → M be a smooth G-action on a smooth and closed manifold M. Suppose that the fixed point set of consists of two connected components, F n and F n−1 , with dimensions n and n − 1, respectively. In this paper we prove that, if in the fixed data of at least two eigenbundles over F n have dimension greater than n, and at least one eigenbundle over F n−1 has dimension greater than n − 1, then the action (M, ) bounds equivariantly. It is well known that, if T : M m → M m is a smooth involution on a smooth and closed m-dimensional manifold M m such that the fixed point set of T has constant dimension n, and if m > 2n, then (M m , T ) bounds equivariantly; this fact was proved by R. E. Stong and C. Kosniowski 27 years ago. As a consequence of our result, we will see that the same fact is true when, besides n-dimensional components, the fixed point set contains additional (n − 1)-dimensional components.
Mathematics Subject Classifications (2000). Primary 57R85, Secondary 57R75.