Counting points of slope varieties over finite fields.
Counting rooted trees: the universal law .
Counting set covers and split graphs.
Counting triangulations of planar point sets.
Counting two-graphs related to trees.
Counting unlabelled topologies and transitive relations.
Counting unrooted maps using tree-decomposition.
Coûts moyens de circuits hamiltoniens de de
Cover matrices of posets and their spectra
We analyze the spectra of the cover matrix of a given poset. Some consequences on the multiplicities are provided.
Covering and packing in graphs. III: Cyclic and acyclic invariants
Covering energy of posets and its bounds
The concept of covering energy of a poset is known and its McClelland type bounds are available in the literature. In this paper, we establish formulas for the covering energy of a crown with elements and a fence with elements. A lower bound for the largest eigenvalue of a poset is established. Using this lower bound, we improve the McClelland type bounds for the covering energy for some special classes of posets.
Covering graphs and subdirect decompositions of partially ordered sets
Coverings, heat kernels and spanning trees.
Coverings, Laplacians, and heat kernels of directed graphs.
Covers of digraphs
Coxeter polynomials of Salem trees
We compute the Coxeter polynomial of a family of Salem trees, and also the limit of the spectral radii of their Coxeter transformations as the number of their vertices tends to infinity. We also prove that if z is a root of multiplicities for the Coxeter polynomials of the trees respectively, then z is a root for the Coxeter polynomial of their join, of multiplicity at least where .
Criteria for of the existence of uniquely partitionable graphs with respect to additive induced-hereditary properties
Let ₁,₂,...,ₙ be graph properties, a graph G is said to be uniquely (₁,₂, ...,ₙ)-partitionable if there is exactly one (unordered) partition V₁,V₂,...,Vₙ of V(G) such that for i = 1,2,...,n. We prove that for additive and induced-hereditary properties uniquely (₁,₂,...,ₙ)-partitionable graphs exist if and only if and are either coprime or equal irreducible properties of graphs for every i ≠ j, i,j ∈ 1,2,...,n.
Critical Graphs for R(P n , P m ) and the Star-Critical Ramsey Number for Paths
The graph Ramsey number R(G,H) is the smallest integer r such that every 2-coloring of the edges of Kr contains either a red copy of G or a blue copy of H. The star-critical Ramsey number r∗(G,H) is the smallest integer k such that every 2-coloring of the edges of Kr − K1,r−1−k contains either a red copy of G or a blue copy of H. We will classify the critical graphs, 2-colorings of the complete graph on R(G,H) − 1 vertices with no red G or blue H, for the path-path Ramsey number. This classification...
Critical subgraphs of a random graph.
Criticality concepts in geodetic graphs