Rational Isogenies of Prime Degree.
Given a closed Riemann surface R of genus p ≥ 2 together with an anticonformal involution τ : R ---> R with fixed points, we consider the group K(R, τ) consisting of the conformal and anticonformal automorphisms of R which commute with τ...
We derive a relation between induced representations on the group which implies a relation between the jacobians of certain modular curves of level . The motivation for the construction of this relation is the determination of the applicability of Mazur’s method to the modular curve associated to the normalizer of a non-split Cartan subgroup of .