Articles de revista: Recent submissions
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Rainbow spanning subgraphs in bounded edge–colourings of graphs with large minimum degree
(20170801)
Article
Open AccessWe study the existence of rainbow perfect matching and rainbow Hamiltonian cycles in edge–colored graphs where every color appears a bounded number of times. We derive asymptotically tight bounds on the minimum degree of ... 
On sets defining few ordinary planes
(20170919)
Article
Open AccessLet S be a set of n points in real threedimensional space, no three collinear and not all coplanar. We prove that if the number of planes incident with exactly three points of S is less than (Formula presented.) for some ... 
A generalisation of Sylvester's problem to higher dimensions
(20170701)
Article
Open AccessIn this article we consider $S$ to be a set of points in $d$space with the property that any $d$ points of $S$ span a hyperplane and not all the points of $S$ are contained in a hyperplane. The aim of this article is to ... 
A finite version of the Kakeya problem
(20160602)
Article
Open AccessLet L be a set of lines of an affine space over a field and let S be a set of points with the property that every line of L is incident with at least N points of S. Let D be the set of directions of the lines of L considered ... 
On quotient digraphs and voltage digraphs
(201710)
Article
Open AccessWe study the relationship between two key concepts in the theory of digraphs, those of quotient digraphs and voltage digraphs. These techniques contract or expand a given digraph in order to study its characteristics,or ... 
The spectra of subKautz and cyclic Kautz digraphs
(Elsevier, 20171015)
Article
Open AccessKautz digraphs K(d,l) are a wellknown family of dense digraphs, widely studied as a good model for interconnection networks. Closely related with these, the cyclic Kautz CK(d,l) and the subKautz sK(d,2) digraphs were ... 
A new labeling construction from the product
(20170801)
Article
Open AccessThe ¿hproduct that is referred in the title was introduced in 2008 as a generalization of the Kronecker product of digraphs. Many relations among labelings have been obtained since then, always using as a second factor a ... 
The number and degree distribution of spanning trees in the Tower of Hanoi graph
(20160104)
Article
Open AccessThe number of spanning trees of a graph is an important invariant related to topological and dynamic properties of the graph, such as its reliability, communication aspects, synchronization, and so on. However, the practical ... 
Iterated line digraphs are asymptotically dense
(Elsevier, 2017)
Article
Open AccessWe show that the line digraph technique, when iterated, provides dense digraphs, that is, with asymptotically large order for a given diameter (or with small diameter for a given order). This is a well known result for ... 
The normalized Laplacian spectrum of subdivisions of a graph
(20160805)
Article
Open AccessDetermining and analyzing the spectra of graphs is an important and exciting research topic in mathematics science and theoretical computer science. The eigenvalues of the normalized Laplacian of a graph provide information ... 
On perfect and quasiperfect dominations in graphs
(20170227)
Article
Open AccessA subset S ¿ V in a graph G = ( V , E ) is a k quasiperfect dominating set (for k = 1) if every vertex not in S is adjacent to at least one and at most k vertices in S . The cardinality of a minimum k quasiperfect ... 
Perfect (super) EdgeMagic Crowns
(20170106)
Article
Open AccessA graph G is called edgemagic if there is a bijective function f from the set of vertices and edges to the set {1,2,…,V(G)+E(G)} such that the sum f(x)+f(xy)+f(y) for any xy in E(G) is constant. Such a function is ...