On contractible (n + 3)-manifolds

In 1961, Mazur constructed a contractible, compact, smooth 4-manifold with boundary which is not homeomorphic to the standard 4-ball. In this talk, for any integer n ≥ 2 we construct a contractible, compact, smooth (n + 3)-manifold with boundary which is not homeomorphic to the standard (n + 3)-ball.