Torsions in Cohomology of arithmetic groups and congruence of modular forms
Time: Thu, 27 Jun 2019, 13:30-15:05
Place: First conference room at Jinchunyuan West Building (近春园西楼)
Speaker: Taiwang Deng (Max Planck institute for mathematics)
Abstract:
In this talk I will discuss the torsion classes in the cohomology of SL2(ℤ) as well as its variant with compact support. As a consequence, we show how to deduce congruences of cuspidal forms with Eisenstein classes modulo small primes. This generalizes the previous result on Ramanujan tau functions.