Title: Class numbers of ring class fields of prime conductor
Abstract: Let K be an imaginary quadratic field with class number one and let p be a prime not dividing 6dK . In this paper we generalize an algorithm of Schoof to compute l-parts of the class numbers of ring class fields L of conductor p < 200 for l < 1000. We achieve this by using elliptic units analytically constructed by Stark and the Galois action on them given by Shimura’s reciprocity law.