Subdivision yields Alexander duality on independence complexes.
Subdominant eigenvalues for stochastic matrices with given column sums.
Subfield permutation polynomials and orthogonal subfield systems in finite fields
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.
Subplane replacement in projective planes.
Subsemi-Eulerian graphs.
Subsequence containment by involutions.
Subsets of the unit ball the are separated by more than one
Substitutions, abstract number systems and the space filling property
In this paper we study multi-dimensional words generated by fixed points of substitutions by projecting the integer points on the corresponding broken halfline. We show for a large class of substitutions that the resulting word is the restriction of a linear function modulo and that it can be decided whether the resulting word is space filling or not. The proof uses lattices and the abstract number system associated with the substitution.
Substitutions on two letters, cutting segments and their projections
In this paper we study the structure of the projections of the finite cutting segments corresponding to unimodular substitutions over a two-letter alphabet. We show that such a projection is a block of letters if and only if the substitution is Sturmian. Applying the procedure of projecting the cutting segments corresponding to a Christoffel substitution twice results in the original substitution. This induces a duality on the set of Christoffel substitutions.
Subtree Matching by Pushdown Automata
Succession rules and deco polyominoes
Succession rules and Deco polyominoes
In this paper, we examine the class of "deco" polyominoes and the succession rule describing their construction. These polyominoes are enumerated according to their directed height by factorial numbers. By changing some aspects of the "factorial" rule, we obtain some succession rules that describe various "deco" polyomino subclasses. By enumerating the subclasses according to their height and width, we find the following well-known numbers: Stirling numbers of the first and second kind,...
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.