“On the class group of cyclotomic fields”
Martedì 10 Febbraio 2026, ore 17:00 - Aula 2AB45 - Chiara Sabadin (University of Regensburg)
Abstract
Class groups of fields give important information about unique factorisation in their ring of integers, in particular they played a major role in the study of Fermat’s Last Theorem. In this talk we will first introduce what class groups are and then, following the last 200 years of mathematical progress in the topic, introduce Ribet’s Method, a powerful technique combining modular forms and Galois representations, used to study class groups. We will end with a new cohomological approach to this method.
