6 papers
Real-rooted flow polynomials have only integral roots
Meiqiao Zhang, Fengming Dong
Let be a connected bridgeless graph. In 2011, Kung and Royle showed that all roots of the flow polynomial of are integers if and only if is the dual of a chord…
Non-persistence of equality between chromatic polynomials and list-color functions
Meiqiao Zhang, Fengming Dong
For any graph , let and denote the chromatic polynomial and the list-color function of , respectively. It remains an open problem whether, for every…
A study on -equivalent graphs
Fengming Dong, Meiqiao Zhang
In his article [J. Comb. Theory Ser. B 16 (1974), 168-174], Tutte called two graphs -equivalent (i.e., codichromatic) if they have the same Tutte polynomial and showed that grap…
On the colorability of bi-hypergraphs
Meiqiao Zhang, Fengming Dong, Ruixue Zhang
A {\it mixed hypergraph} consists of the vertex set and two families of subsets of : the family of co-edge…
DP color functions versus chromatic polynomials (II)
Meiqiao Zhang, Fengming Dong
For any connected graph , let and denote the chromatic polynomial and DP color function of , respectively. It is known that hol…
Properties of chromatic polynomials of hypergraphs not held for chromatic polynomials of graphs
Ruixue Zhang, Fengming Dong
In this paper, we present some properties on chromatic polynomials of hypergraphs which do not hold for chromatic polynomials of graphs. We first show that chromatic polynomials of…