Isolated and sporadic points on modular curvesMPIM

by Filip Najman (University of Zagreb/z. Z. MPIM)

Wednesday Oct 7, 2026, 2:30 PM → 3:30 PM Europe/Berlin

MPIM, Vivatsgasse, 7 - Lecture Hall (Max Planck Institute for Mathematics)

Number theory lunchs seminar

 

A point of degree d on a curve is sporadic if the curve has only finitely many points of degree at most d. It is isolated if it doesn't lie in a geometric family of points of the same degree. On modular curves, these points correspond to elliptic curves with unexpected level structure over number fields of small degree. I will survey general results on isolated and sporadic points on modular curves, then present recent work on sporadic points on  the modular curves X_0(n) and X_1(n).