EJC
2016
8 years 8 months ago
2016
We continue to explore cyclotomic factors in the descent set polynomial Qn(t), which was introduced by Chebikin, Ehrenborg, Pylyavskyy and Readdy. We obtain large classes of facto...
EJC
2016
8 years 8 months ago
2016
We study “positive” graphs that have a nonnegative homomorphism number into every edge-weighted graph (where the edgeweights may be negative). We conjecture that all positive ...
EJC
2016
8 years 8 months ago
2016
The well known dichotomy conjecture of Feder and Vardi states that for every family Γ of constraints CSP(Γ) is either polynomially solvable or NP-hard. Bulatov and Jeavons reform...
EJC
2016
8 years 8 months ago
2016
Abstract. Building on recent results regarding symmetric probabilistic constructions of countable structures, we provide a method for constructing probability measures, concentrate...
EJC
2016
8 years 8 months ago
2016
We give a survey of some general results on graph limits associated to hereditary classes of graphs. As examples, we consider some classes defined by forbidden subgraphs and some ...
EJC
2016
8 years 8 months ago
2016
For r ≥ 2, an r-uniform hypergraph is called a friendship r-hypergraph if every set R of r vertices has a unique ‘friend’ – that is, there exists a unique vertex x /∈ R ...
EJC
2016
8 years 8 months ago
2016
Let n ≥ k ≥ l ≥ 2 be integers, and let F be a family of k-element subsets of an n-element set. Suppose that l divides the size of the intersection of any two (not necessarily...
EJC
2016
8 years 8 months ago
2016
zed Dyck tilings (Extended Abstract) Matthieu Josuat-Verg´es1∗ and Jang Soo Kim 2† 1 IGM, Universit´e de Marne-la-Vall´ee, France 2 Department of Mathematics, Sungkyunkwan U...
EJC
2016
8 years 8 months ago
2016
In this paper we prove that there exists an absolute constant c > 0 such that for every natural number k, every non-bipartite 2-connected graph with average degree at least ck ...
EJC
2016
8 years 8 months ago
2016
Abstract. In this note we investigate some matroid minor structure results. In particular, we present sufficient conditions, in terms of triangles, for a matroid to have either U2,...