Cubic Partial Cubes from Simplicial Arrangements

We show how to construct a cubic partial cube from any simplicial arrangement of lines or pseudolines in the projective plane. As a consequence, we find nine new infinite families of cubic partial cubes as well as many sporadic examples.Comment: 11 pages, 10 figure

On the geodesic pre-hull number of a graph

AbstractGiven a convexity space X whose structure is induced by an interval operator I, we define a parameter, called the pre-hull number of X, which measures the intrinsic non-convexity of X in terms of the number of iterations of the pre-hull operator associated with I which are necessary in the worst case to reach the canonical extension of copoints of X when they are being extended by the adjunction of an attaching point. We consider primarily the geodesic convexity structure of connected graphs in the case where the pre-hull number is at most 1, with emphasis on bipartite graphs, in particular, partial cubes

Weak geodesic topology and fixed finite subgraph theorems in infinite partial cubes I. Topologies and the geodesic convexity

AbstractThe weak geodesic topology on the vertex set of a partial cube G is the finest weak topology on V(G) endowed with the geodesic convexity. We prove the equivalence of the following properties: (i) the space V(G) is compact; (ii) V(G) is weakly countably compact; (iii) the vertex set of any ray of G has a limit point; (iv) any concentrated subset of V(G) (i.e. a set A such that any two infinite subsets of A cannot be separated by deleting finitely many vertices) has a finite positive number of limit points. Moreover, if V(G) is compact, then it is scattered. We characterize the partial cubes for which the weak geodesic topology and the geodesic topology (see [N. Polat, Graphs without isometric rays and invariant subgraph properties I. J. Graph Theory27 (1998), 99–109]) coincide, and we show that the class of these particular partial cubes is closed under Cartesian products, retracts and gated amalgams

Tribes of cubic partial cubes

Graphs and Algorithm

Partial cubes as subdivision graphs and as generalized Petersen graphs

Isometric subgraphs of hypercubes are known as partial cubes. The subdivision graph of a graph G is obtained from G by subdividing every edge of G. It is proved that for a connected graph G its subdivision graph is a partial cube if and only if every block of G is either a cycle or a complete graph. Regular partial cubes are also considered. In particular it is shown that among the generalized Petersen graphs, P (10; 3) and P (2n; 1), n 2, are the (regular) partial cubes.