GALaC team at LRI, Paris-Sud
GALaC is a research group at LRI, Paris-Sud University. We are focused on graph theory, combinatorics and network distributed systems algorithmic.
Mobius functions for real hyperplane arrangements.
We discuss the beginnings of a theory of noncommutative Mobius functions and its connections to the structure of the algebra of faces of a hyperplane arrangement. It is to be seen as a generalization of the theory of Mobius functions for lattices, developed by Rota and his school in the ...
A proof-theoretic analysis of the rotation lattice of binary trees
Join seminar with the Parsifal team The classical Tamari lattice Yn is defined as the set of binary trees with n internal nodes, with the partial ordering induced by the (right) rotation operation. It is not obvious why Yn is a lattice, but this was first proved by Haya Friedman ...
Generalized Jucys-Murphy elements and canonical idempotents in towers of algebras
The collection of symmetric group algebras serves as a motivating example for what I'll call a multiplicity-free tower of finite dimensional algebras. Any such family has a canonical complete set of pairwise orthogonal primitive idempotents stemming from its representation theory. In the case of the symmetric group algebras, these ...