题目：The derived modular group

报告人： Loic Merel（Universite Pierre and Maire Curie, Paris）

时间：6月12日，10:00-11:30

地点：明德楼B区201学术报告厅

摘要：The modular group (SL_2(Z)) is among the most famous groups in mathematics, and the basis for the theory of modular forms etc.  Its derived subgroup is cocyclic of index 12, and the subject of a thin and not very well known literature. However, it is the source of delightful mathematics, that we will review before considering the use of this group for Manin's theory of modular symbols (Manin's theory will be recalled from scratch).