# Meeting Details

Title: On Rankin-Cohen Deformations Algebra and Number Theory Seminar Yi-Jun Yao, Penn State University Arising from the study of deformation question related to modular forms,Rankin-Cohen brackets are bidifferential operators which produce new modular forms from two "old" ones. Starting from early 90's,related deformation theories are developed first by Cohen-Manin-Zagier, and then later (in a more general framework) by Connes-Moscovici (thus linked to noncommutative geometry). We will discuss the relations between these objects and the unitary representations of $SL_2({mathbb R})$, and some combinatorial questions that appeared in these studies.