Kathy Q. Ji

collaborators

3 papers

math.CO2026

On the distributions of the statistics (des, maj, inv) over several classes of permutations

Guo-Niu Han, Kathy Q. Ji, Huan Xiong

We investigate the joint distribution of the trivariate statistics (des, maj, inv) on classical permutations, Andre permutations of the first and second kinds, and Simsun permutati…

math.CO2026

Modular Nahm sums for symmetrizable matrices of indices $(2, \dots, 2, 1)$ and $(1, \dots, 1, 2)$

Julia Q. D. Du, Kathy Q. Ji, Erin Y. Y. Shen +1

In this paper, we present three families of modular Nahm sums for symmetrizable matrices with arbitrary rank $r \geq 2$ of indices $(2, \dots, 2, 1)$ and $(1, \dots, 1, 2)$ . Speci…

math.CO2025

Inverse descent statistic for André and simsun permutations

Guo-Niu Han, Kathy Q. Ji, Huan Xiong

Simsun permutations, André I permutations and André II permutations are three combinatorial models for Euler numbers. It's known that the descent statistic is equidistributed over…

On the distributions of the statistics (des, maj, inv) over several classes of permutations

Modular Nahm sums for symmetrizable matrices of indices (2,…,2,1) and (1,…,1,2)

Inverse descent statistic for André and simsun permutations

Modular Nahm sums for symmetrizable matrices of indices $(2, \dots, 2, 1)$ and $(1, \dots, 1, 2)$