We study the VC-dimension of the set system on the vertex set of some graph which is induced by the family of its k-connected subgraphs. In particular, we give tight upper and lower bounds for the VC-dimension. Moreover, we show that computing the VC-dimension is NP-complete and that it remains NP-complete for split graphs and for some subclasses of planar bipartite graphs in the cases k = 1 an...

We study the node-deletion problem consisting of finding a maximum weighted induced bipartite subgraph of a planar graph with maximum degree three. We show that this is polynomially solvable. It was shown in [4] that it is NP-complete if the maximum degree is four. We also extend these ideas to the problem of balancing signed graphs. We also consider maximum weighted induced acyclic subgraphs o...

The partition of graphs into “nice” subgraphs is a central algorithmic problem with strong ties to matching theory. We study the partitioning of undirected graphs into same-size stars, a problem known to be NPcomplete even for the case of stars on three vertices. We perform a thorough computational complexity study of the problem on subclasses of perfect graphs and identify several polynomial-t...

In this paper, subgraphs and complementary graphs are used to analyze the network synchronizability. Some sharp and attainable bounds are provided for the eigenratio of the network structural matrix, which characterizes the network synchronizability, especially when the network’s corresponding graph has cycles, chains, bipartite graphs or product graphs as its subgraphs.

A graph is 1-extendible if every edge has a 1-factor containing it. A 1-extendible non-bipartite graph G is said to be near bipartite if there exist edges e1 and e2 such that G − {e1, e2} is 1-extendible and bipartite. We characterise the Pfaffian near bipartite graphs in terms of forbidden subgraphs. The theorem extends an earlier characterisation of Pfaffian bipartite graphs.

Symmetric edge polytopes, a.k.a. PV-type adjacency associated with undirected graphs have been defined and studied in several seemingly independent areas including number theory, discrete geometry, dynamical systems. In particular, the authors are motivated by study of algebraic Kuramoto equations unmixed form whose Newton polytopes symmetric polytopes. The interplay between geometric structure...

A bipartite covering of order k of the complete graph Kn on n vertices is a collection of complete bipartite graphs so that every edge of Kn lies in at least 1 and at most k of them. It is shown that the minimum possible number of subgraphs in such a collection is Θ(kn1/k). This extends a result of Graham and Pollak, answers a question of Felzenbaum and Perles, and has some geometric consequenc...

This is the first half of a two-part paper devoted to on-line 3-colorable graphs. Here on-line 3-colorable triangle-free graphs are characterized by a finite list of forbidden induced subgraphs. The key role in our approach is played by the family of graphs which are both triangleand (2K2 + K1)-free. Characterization of this family is given by introducing a bipartite modular decomposition conce...