Structures algébriques généralisées des problèmes de cheminement dans les graphes
Structures ofW(2.2) Lie conformal algebra
The purpose of this paper is to study W(2, 2) Lie conformal algebra, which has a free ℂ[∂]-basis L, M such that [...] [LλL]=(∂+2λ)L,[LλM]=(∂+2λ)M,[MλM]=0 . In this paper, we study conformal derivations, central extensions and conformal modules for this Lie conformal algebra. Also, we compute the cohomology of this Lie conformal algebra with coefficients in its modules. In particular, we determine its cohomology with trivial coefficients both for the basic and reduced complexes.
Subarborians
Subdeterminants and subgraphs
Subdivision yields Alexander duality on independence complexes.
Subdominant eigenvalues for stochastic matrices with given column sums.
Subgraph densities in hypergraphs
Let r ≥ 2 be an integer. A real number α ∈ [0,1) is a jump for r if for any ε > 0 and any integer m ≥ r, any r-uniform graph with n > n₀(ε,m) vertices and density at least α+ε contains a subgraph with m vertices and density at least α+c, where c = c(α) > 0 does not depend on ε and m. A result of Erdös, Stone and Simonovits implies that every α ∈ [0,1) is a jump for r = 2. Erdös asked whether the same is true for r ≥ 3. Frankl and Rödl gave a negative answer by showing an infinite sequence...
Subgraph densities in signed graphons and the local Simonovits-Sidorenko conjecture.
Subgraph isomorphism in planar graphs and related problems.
Sublattices of certain Coxeter lattices
In this paper, we describe the sublattices of some lattices, extending previous results of [Ber]. Our description makes intensive use of graphs.
Subsemi-Eulerian graphs.
Subtree Matching by Pushdown Automata
Sudoku graphs are integral.
Sufficient conditions for edge-locally connected and -connected graphs
Sufficient conditions for locally connected graphs
Sufficient conditions for planar graphs to be 2-distance ()-colourable.
Sufficient conditions for the minimum 2-distance colorability of plane graphs of girth 6.
Sum labellings of cycle hypergraphs
A hypergraph is a sum hypergraph iff there are a finite S ⊆ IN⁺ and d̲, [d̅] ∈ IN⁺ with 1 < d̲ ≤ [d̅] such that is isomorphic to the hypergraph where V = S and . For an arbitrary hypergraph the sum number σ = σ() is defined to be the minimum number of isolated vertices such that is a sum hypergraph. Generalizing the graph Cₙ we obtain d-uniform hypergraphs where any d consecutive vertices of Cₙ form an edge. We determine sum numbers and investigate properties of sum labellings for this...
Sum list coloring arrays.
Sum List Edge Colorings of Graphs
Let G = (V,E) be a simple graph and for every edge e ∈ E let L(e) be a set (list) of available colors. The graph G is called L-edge colorable if there is a proper edge coloring c of G with c(e) ∈ L(e) for all e ∈ E. A function f : E → ℕ is called an edge choice function of G and G is said to be f-edge choosable if G is L-edge colorable for every list assignment L with |L(e)| = f(e) for all e ∈ E. Set size(f) = ∑e∈E f(e) and define the sum choice index χ′sc(G) as the minimum of size(f) over all edge...