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# Abstract L. Gehrmann

**Lennart Gehrmann ** will speak on

** Derived Hecke algebras and automorphic L-Invariants **

Abstract: Hilbert modular forms of parallel weight two only show up in the middle cohomology of the appropiate locally symmetric space. The analogous automorphic forms over number fields of arbitrary sign (e.g. Bianchi modular forms) show up in several degrees. In this talk we define automorphic L-Invariants for each of these degrees and conjecture that they are essentially the same. We relate our conjecture to Venkatesh's conjectures on derived Hecke algebras.