期刊： JOURNAL OF COMBINATORIAL THEORY SERIES B, 2021; 149 ()
Let G = (V, E) be a graph. A proper total weighting of G is a mapping w : V boolean OR E -> R such that the following sum for each v is an element ......
期刊： JOURNAL OF COMBINATORIAL THEORY SERIES B, 2021; 147 ()
Let f(r)(n, v, e) denote the maximum number of edges in an r-uniform hypergraph on n vertices, in which the union of any e distinct edges contains at ......
期刊： JOURNAL OF COMBINATORIAL THEORY SERIES B, 2021; 149 ()
This paper gives a solution of Problem 1.8 in [16]. As a corollary, it is shown that every connected non-bipartite Cayley graph on a solvable group of......
期刊： JOURNAL OF COMBINATORIAL THEORY SERIES B, 2021; 150 ()
An edge cut C of a graph G is tight if vertical bar C boolean AND M vertical bar = 1 for every perfect matching M of G. Barrier cuts and 2-separation ......
期刊： JOURNAL OF COMBINATORIAL THEORY SERIES B, 2021; 149 ()
We present two extremal results on 4-cycles. Let q be a large even integer. First we prove that every (q(2) + q + 1)-vertex C-4-free graph with more t......
期刊： JOURNAL OF COMBINATORIAL THEORY SERIES B, 2021; 147 ()
In the present paper, we introduce the notion of graph functionality, which generalises simultaneously several other graph parameters, such as degener......
期刊： JOURNAL OF COMBINATORIAL THEORY SERIES B, 2021; 147 ()
We start up the study of the stability of general graph pairs. This notion is a generalization of the concept of the stability of graphs. We say that ......
期刊： JOURNAL OF COMBINATORIAL THEORY SERIES B, 2021; 149 ()
In 1983, Bouchet proposed a conjecture that every flow admissible signed graph admits a nowhere-zero 6-flow. Bouchet himself proved that such signed g......
期刊： JOURNAL OF COMBINATORIAL THEORY SERIES B, 2021; 150 ()
A reductive characterization of arc-transitive circulants was given independently by Kov & aacute;cs in 2004 and the first author in 2005. In this......
期刊： JOURNAL OF COMBINATORIAL THEORY SERIES B, 2021; 146 ()
Hedetniemi conjectured in 1966 that chi(G x H) = min{chi(G), chi(H)} for all graphs G and H. Here G x H is the graph with vertex set V(G) x V(H) defin......
期刊： JOURNAL OF COMBINATORIAL THEORY SERIES B, 2021; 146 ()
For a 2-connected graph G on n vertices and two vertices x, y is an element of V (G), we prove that there is an (x, y)-path of length at least k, if t......
期刊： JOURNAL OF COMBINATORIAL THEORY SERIES B, 2020; 144 ()
Seymour and, independently, Kelmans conjectured in the 1970s that every 5-connected nonplanar graph contains a subdivision of K-5. This conjecture was......
期刊： JOURNAL OF COMBINATORIAL THEORY SERIES B, 2020; 145 ()
This paper proves that every planar graph G contains a matching M such that the Alon-Tarsi number of G - M is at most 4. As a consequence, G - M is 4-......
期刊： JOURNAL OF COMBINATORIAL THEORY SERIES B, 2020; 145 ()
This paper consists of two major parts. In the first part, the relations between Tutte orientations and circular flows are explored. Tutte orientation......
期刊： JOURNAL OF COMBINATORIAL THEORY SERIES B, 2020; 145 ()
A graph Gamma admitting a group H of automorphisms acting semi-regularly on the vertices with exactly two orbits is called a bi-Cayley graph over H. T......
