Suppose π = (d1, d2, . . . , dn) and π = (d1, d ′ 2 , . . . , dn) are two positive nonincreasing degree sequences, write π ⊳ π if and only if π 6= π, ∑n i=1 di = ∑n i=1 d ′ i, and ∑j i=1 di ≤ ∑j i=1 di for all j = 1, 2, . . . , n. Let ρ(G) and μ(G) be the spectral radius and signless Laplacian spectral radius of G, respectively. Also let G and G be the extremal graphs with the maximal (signless...

The concept of the matching polynomial of a graph, introduced by Farrell in 1979, has received considerable attention and research. In this paper, we generalize this concept and introduce the matching polynomial of hypergraphs. A recurrence relation of the matching polynomial of a hypergraph is obtained. The exact matching polynomials of some special hypergraphs are given. Further, we discuss t...

this paper presents the application of the matching pursuit method to model synchronous generator. this method is useful for online analysis. in the proposed method, the field voltage is considered as input signal, while the terminal voltage and active power of the generator are output signals. usually, the difference equation with a second degree polynomial structure is used to estimate the co...

In this paper we study various extremal problems related to some combinatorially defined graph polynomials such as matching polynomial, chromatic polynomial, Laplacian polynomial. It will turn out that many problems attain its extremal value in the class of threshold graphs. To attack these kinds of problems we survey several applications of the so-called Kelmans transformation. Mea culpa. This...

In this paper, we study graphs with integer matching polynomial roots. We characterize all traceable graphs whose all matching polynomial roots are integer. We show that there is no k-regular claw-free graph (k ≥ 2), whose all matching polynomial roots are integer. Also we conjecture that apart from K7 \ (E(C3) ∪E(C4)), there is no matching integral k-regular graph (k ≥ 2). 2010 Mathematics Sub...

We discuss the complexity of computing various graph polynomials of graphs of fixed clique-width. We show that the chromatic polynomial, the matching polynomial and the two-variable interlace polynomial of a graph G of clique-width at most k with n vertices can be computed in time O(n), where f(k) ≤ 3 for the inerlace polynomial, f(k) ≤ 2k + 1 for the matching polynomial and f(k) ≤ 3 · 2 for th...