1 citations · 1 across the 5 of their papers we have counts for
8 papers
Unimodality of independence polynomials of two family of trees
Grace M. X. Li
In 1987, Alavi, Malde, Schwenk and Erdős conjectured that the independence polynomials of trees are unimodal. Subsequently, many researchers proposed strengthening this conjecture…
A symmetric function approach to log-concavity of independence polynomials
Ethan Y. H. Li, Grace M. X. Li, Arthur L. B. Yang +1
As introduced by Gutman and Harary, the independence polynomial of a graph serves as the generating polynomial of its independent sets. In 1987, Alavi, Malde, Schwenk and Erdős con…
Strongly nice property and Schur positivity of graphs
Ethan Y. H. Li, Grace M. X. Li, Arthur L. B. Yang +1
Motivated by the notion of nice graphs, we introduce the concept of strongly nice property, which can be used to study the Schur positivity of symmetric functions. We show that a g…
Stanley's conjecture on the Schur positivity of distributive lattices
Grace M. X. Li, Dun Qiu, Arthur L. B. Yang +1
In this paper we solve an open problem on distributive lattices, which was proposed by Stanley in 1998. This problem was motivated by a conjecture due to Griggs, which equivalently…
A planar network proof for Hankel total positivity of type Narayana polynomials
Ethan Y. H. Li, Grace M. X. Li, Arthur L. B. Yang +1
The Hankel matrix of type B Narayana polynomials was proved to be totally positive by Wang and Zhu, and independently by Sokal. Pan and Zeng raised the problem of giving a planar n…
Immanant Positivity for Catalan-Stieltjes Matrices
Ethan Y. H. Li, Grace M. X. Li, Arthur L. B. Yang +1
In this paper we give some sufficient conditions for the nonnegativity of immanants of square submatrices of Catalan-Stieltjes matrices and their corresponding Hankel matrices. To…
The twinning operation on graphs does not always preserve -positivity
Ethan Y. H. Li, Grace M. X. Li, David G. L. Wang +1
Motivated by Stanley's -free conjecture on chromatic symmetric functions, Foley, Hoàng and Merkel introduced the concept of strong -positivity and conjectured th…
The -positivity of two families of -free graphs
Grace M. X. Li, Arthur L. B. Yang
Motivated by Stanley's conjecture about the -positivity of claw-free incomparability graphs, Hamel and her collaborators studied the -positivity of -free graphs, w…