Séminaire Algèbre et Arithmétique - Salle de conférences du CMLS - 14h15
28 nov. 2025
14h15 – Marti Roset (IMJ-PRG)
Titre: Rigid classes for SL(n) and their values at special points.
Abstract: The theory of complex multiplication implies that the values of modular functions at CM points belong to abelian extensions of imaginary quadratic fields. In this talk, we propose a conjectural extension of this phenomenon to the setting of totally real fields. Generalizing the work of Darmon, Pozzi, and Vonk, we construct rigid classes for SL(n), which play the role of modular functions, and define their values at points associated with totally real fields. The construction of these classes originates from a topological source: the Eisenstein class of a torus bundle. This is ongoing joint work with Peter Xu.