Some homology lens spaces which bound rational homology balls

Abstract

A homology lens space is a smooth closed 3-manif old M* with H k (M & )-H k (L(p,l)) for all k (p some nonnegative integer). When p-1 M z is a homology 3-sphere. It is an open question which of these homology lens spaces bound rational homology balls and of special interest which homology 3-spheres bound contractible manifolds. In this note we answer this question for certain Seifert fibre spaces, each with three exceptional fibres.