| In this thesis, we study the Heegaard Floer homology of 3-manifolds which is introduced by Peter Ozsvath and Zoltan Szabo. We first look at certain Brieskorn homology spheres. We then consider the question of which 3-manifolds bound rational homology 4-balls, and give partial answer in the case of Brieskorn homology spheres Sigma(p, q, r) with small values for p, q, r using the obstruction d defined through cobordism maps between Heegaard Floer homologies. |
