activity
20152020
most citedPattern-avoiding alternating words

1 citations · 1 across the 4 of their papers we have counts for

collaborators

13 papers

math.CO2020

Plateaux on generalized Stirling permutations and partial -positivity

Zhicong Lin, Jun Ma, Philip B. Zhang

We prove that the enumerative polynomials of generalized Stirling permutations by the statistics of plateaux, descents and ascents are partial -positive. Specialization of our r…

math.CO2019

Chromatic nonsymmetric polynomials of Dyck graphs are slide-positive

Vasu Tewari, Andrew Timothy Wilson, Philip B. Zhang

Motivated by the study of Macdonald polynomials, J. Haglund and A. Wilson introduced a nonsymmetric polynomial analogue of the chromatic quasisymmetric function called the \emph{ch…

math.CO2019

Distributions of several infinite families of mesh patterns

Sergey Kitaev, Philip B. Zhang, Xutong Zhang

Brändén and Claesson introduced mesh patterns to provide explicit expansions for certain permutation statistics as linear combinations of (classical) permutation patterns. The firs…

math.CO2019

Equivariant Kazhdan-Lusztig polynomials of thagomizer matroids

Matthew H. Y. Xie, Philip B. Zhang

The equivariant Kazhdan-Lusztig polynomial of a matroid was introduced by Gedeon, Proudfoot, and Young. Gedeon conjectured an explicit formula for the equivariant Kazhdan-Lusztig p…

math.CO2019

Real-rootedness of variations of Eulerian polynomials

James Haglund, Philip B. Zhang

The binomial Eulerian polynomials, introduced by Postnikov, Reiner, and Williams, are -positive polynomials and can be interpreted as -polynomials of certain flag simplicial…

math.CO2018

Distributions of mesh patterns of short lengths

Sergey Kitaev, Philip B. Zhang

A systematic study of avoidance of mesh patterns of length 2 was conducted by Hilmarsson et al., where 25 out of 65 non-equivalent cases were solved. In this paper, we give 27 dist…