Colloquium
DATE	2020-11-26　16:10-17:00
PLACE	數學館3174教室
SPEAKER	葉永南 研究員（中央研究院數學研究所）
TITLE	Chen’s Grammars and Several Applications in Combinatorics (II)
ABSTRACT	In this talk, we first apply the change of grammars method to study gamma-positivity and partial gamma-positivity of descent-type polynomials. We then show the symmetry of the coefficients polynomials of the Jacobi elliptic function sn(u,k). At last, we show the semi-gamma-positivity of the alternating runs polynomials of dual Stirling permutations.