On minimum leaf spanning trees and a criticality notion

The minimum leaf number of a connected non-hamiltonian graph G is the number of leaves of a spanning tree of G with the fewest leaves among all spanning trees of G. Based on this quantity, Wiener introduced leaf-stable and leaf-critical graphs, concepts which generalise hypotraceability and hypohamiltonicity. In this article, we present new methods to construct leaf-stable and leaf-critical graphs and study their properties. Furthermore, we improve several bounds related to these families of graphs. These extend previous results of Horton, Thomassen, and Wiener.