Title：         Gamma-positivity for the Eulerian distribution on separable permutations

Speaker：      Shishuo Fu (Chongqing University)

Time&Venue： 2015.08.27  15:00pm  N205

Abstract:      In this talk, we introduce the descent polynomial on separable permutations  (3142 and 2413 avoiding). We 

                    prove that it is gamma-positive, which implies both unimodality and symmetry. Moreover, we find a 

                    combinatorial interpretation for its gamma-coefficients which is comparable with that of Eulerian polynomials. 

                    This is joint work with Zhicong Lin and Jiang Zeng.