Increasing trees and Kontsevich cycles.
In-degree sequence in a general model of a random digraph
A general model of a random digraph D(n,P) is considered. Based on a precise estimate of the asymptotic behaviour of the distribution function of the binomial law, a problem of the distribution of extreme in-degrees of D(n,P) is discussed.
Independence complexes and edge covering complexes via Alexander duality.
Independence complexes of stable Kneser graphs.
Independence number and degree bounded spanning tree.
Independence number and disjoint theta graphs.
Independence number and minimum degree for the existence of -critical graphs.
Independence number of 2-factor-plus-triangles graphs.
Independent cycles and paths in bipartite balanced graphs
Bipartite graphs G = (L,R;E) and H = (L’,R’;E’) are bi-placeabe if there is a bijection f:L∪R→ L’∪R’ such that f(L) = L’ and f(u)f(v) ∉ E’ for every edge uv ∈ E. We prove that if G and H are two bipartite balanced graphs of order |G| = |H| = 2p ≥ 4 such that the sizes of G and H satisfy ||G|| ≤ 2p-3 and ||H|| ≤ 2p-2, and the maximum degree of H is at most 2, then G and H are bi-placeable, unless G and H is one of easily recognizable couples of graphs. This result implies easily that for integers...
Independent Detour Transversals in 3-Deficient Digraphs
In 1982 Laborde, Payan and Xuong [Independent sets and longest directed paths in digraphs, in: Graphs and other combinatorial topics (Prague, 1982) 173-177 (Teubner-Texte Math., 59 1983)] conjectured that every digraph has an independent detour transversal (IDT), i.e. an independent set which intersects every longest path. Havet [Stable set meeting every longest path, Discrete Math. 289 (2004) 169-173] showed that the conjecture holds for digraphs with independence number two. A digraph is p-deficient...
Independent face and vertex covers in plane graphs
INDEPENDENT SET and CLIQUE problems in intersection-defined classes of graphs
Independent sets on path-schemes.
Independent transversal domination in graphs
A set S ⊆ V of vertices in a graph G = (V, E) is called a dominating set if every vertex in V-S is adjacent to a vertex in S. A dominating set which intersects every maximum independent set in G is called an independent transversal dominating set. The minimum cardinality of an independent transversal dominating set is called the independent transversal domination number of G and is denoted by . In this paper we begin an investigation of this parameter.
Independent transversals of longest paths in locally semicomplete and locally transitive digraphs
We present several results concerning the Laborde-Payan-Xuang conjecture stating that in every digraph there exists an independent set of vertices intersecting every longest path. The digraphs we consider are defined in terms of local semicompleteness and local transitivity. We also look at oriented graphs for which the length of a longest path does not exceed 4.
Independent vertex sets in some compound graphs.
Induced Acyclic Tournaments in Random Digraphs: Sharp Concentration, Thresholds and Algorithms
Given a simple directed graph D = (V,A), let the size of the largest induced acyclic tournament be denoted by mat(D). Let D ∈ D(n, p) (with p = p(n)) be a random instance, obtained by randomly orienting each edge of a random graph drawn from Ϟ(n, 2p). We show that mat(D) is asymptotically almost surely (a.a.s.) one of only 2 possible values, namely either b*or b* + 1, where b* = ⌊2(logrn) + 0.5⌋ and r = p−1. It is also shown that if, asymptotically, 2(logrn) + 1 is not within a distance of w(n)/(ln...
Induced complete -partite graphs in dense clique-less graphs.
Induced paths in twin-free graphs.
Induced subgraphs with the same order and size