DIFFUSE OPTICAL LIGHT IN GALAXY CLUSTERS. I. ABELL 3888

We construct an infinite family of hyperbolic 3manifolds whose fundamental groups are cyclically presented. We prove that these 3-manifolds are cyclic branched coverings of S3 over the 2-bridge knot b (17,4). Finally, we compute thehomology groups and discuss the spines of our manifolds which correspond to some group presentations