Speaker
Jean-Bernard Zuber
Description
After reviewing the definition of classical and of free cumulants, and how the latter appear in the limit of large random matrices, I introduce precursors of free cumulants. These precursors have a natural definition, constitute a new family of invariants of Hermitian matrices of finite-size $N$, converge to free cumulants as $N$ tends to infinity, and exhibit several interesting properties that anticipate those of free cumulants. Work in collaboration with Sylvain Lacroix.