A tree t-spanner T in a graph G is a spanning tree of G such that the distance between every pair of vertices in T is at most t times their distance in G. The tree t-spanner proble...
In a finite simple undirected graph, a vertex is simplicial if its neighborhood is a clique. We say that, for k 2, a graph G = (VG, EG) is the k-simplicial power of a graph H = (V...