Seminar des SFB/TRR 326 GAUS Rigid Cocycles and Geodesics on Shimura Curves

Darmon and Vonk's theory of rigid meromorphic cocycles gives a conjectural description of abelian extensions of real quadratic fields akin to the classical theory of complex multiplication. While their conjectures currently seem out of reach, the work of Darmon-Pozzi-Vonk uses p-adic families of Hilbert modular forms to give unconditional results in this direction. I will explain how a reinterpretation in terms of the so-called Kudla programme suggests an approach to extending their results. This point of view also gives a new proof of a theorem of Rickards on intersections of geodesics on Shimura curves, which is related to forthcoming work of Darmon-Vonk.