Results 51 to 60 of about 1,119 (103)
Bounds on F-index of tricyclic graphs with fixed pendant vertices
Open Mathematics, 2020 The F-index F(G) of a graph G is obtained by the sum of cubes of the degrees of all the vertices in G. It is defined in the same paper of 1972 where the first and second Zagreb indices are introduced to study the structure-dependency of total π-electron ...
Akram Sana +2 more
doaj +1 more source
Random algebraic construction of extremal graphs [PDF]
, 2015 In this expository paper, we present a motivated construction of large graphs not containing a given complete bipartite subgraph. The key insight is that the algebraic constructions yield very non-smooth probability distributions.Comment: 8 ...
Bukh, Boris
core
Maximum Edge-Colorings Of Graphs
Discussiones Mathematicae Graph Theory, 2016 An r-maximum k-edge-coloring of G is a k-edge-coloring of G having a property that for every vertex v of degree dG(v) = d, d ≥ r, the maximum color, that is present at vertex v, occurs at v exactly r times. The r-maximum index χr′(G)$\chi _r^\prime (G)$
Jendrol’ Stanislav +1 more
doaj +1 more source
Interval minors of complete bipartite graphs [PDF]
, 2014 Interval minors of bipartite graphs were recently introduced by Jacob Fox in the study of Stanley-Wilf limits. We investigate the maximum number of edges in $K_{r,s}$-interval minor free bipartite graphs. We determine exact values when $r=2$ and describe
Mohar, Bojan +3 more
core
A note on the edge general position number of cactus graphs
Open MathematicsFor a given graph G, a subset S of E(G) is an edge general position set of G if no triple of S is contained in a common shortest path. The cardinality of a largest edge general position set of G is called the edge general position number of G, denoted by
Cao Yahan, Ji Shengjin
doaj +1 more source
The Minimum Harmonic Index for Unicyclic Graphs with Given Diameter
Discussiones Mathematicae Graph Theory, 2018 The harmonic index of a graph G is defined as the sum of the weights 2d(u)+d(v)${2 \over {d(u) + d(v)}}$ of all edges uv of G, where d(u) denotes the degree of a vertex u in G.
Zhong Lingping
doaj +1 more source
Spectral Radius and Hamiltonicity of Graphs
Discussiones Mathematicae Graph Theory, 2019 In this paper, we study the Hamiltonicity of graphs with large minimum degree. Firstly, we present some conditions for a simple graph to be Hamilton-connected and traceable from every vertex in terms of the spectral radius of the graph or its complement,
Yu Guidong +3 more
doaj +1 more source
, 2004 Given a graph G and a configuration C of pebbles on the vertices of G, a pebbling step removes two pebbles from one vertex and places one pebble on an adjacent vertex.
Benjamin Munyan +2 more
core +1 more source
A Note on Upper Bounds for Some Generalized Folkman Numbers
Discussiones Mathematicae Graph Theory, 2019 We present some new constructive upper bounds based on product graphs for generalized vertex Folkman numbers. They lead to new upper bounds for some special cases of generalized edge Folkman numbers, including the cases Fe(K3, K4 − e; K5) ≤ 27 and Fe(K4 −
Xu Xiaodong +2 more
doaj +1 more source
An extremal problem on potentially $K_{m}-P_{k}$-graphic sequences
, 2005 A sequence $S$ is potentially $K_{m}-P_{k}$ graphical if it has a realization containing a $K_{m}-P_{k}$ as a subgraph. Let $\sigma(K_{m}-P_{k}, n)$ denote the smallest degree sum such that every $n$-term graphical sequence $S$ with $\sigma(S)\geq \sigma(
Lai, Chunhui
core +1 more source