Daisy Hamming graphsDravec, Tanja (Avtor) Taranenko, Andrej (Avtor) daisy graphsexpansionisometric subgraphsDaisy graphs of a rooted graph G with the root r were recently introduced as a generalization of daisy cubes, a class of isometric subgraphs of hypercubes. In this paper we first address a problem posed in [A. Taranenko, Daisy cubes: A characterization and a generalization, European J. Combin. 85 (2020) #103058] and characterize rooted graphs G with the root r for which all daisy graphs of G with respect to r are isometric in G, assuming the graph G satisfies the rooted triangle condition. We continue the investigation of daisy graphs G (generated by X) of a Hamming graph H and characterize those daisy graphs generated by X of cardinality 2 thatare isometric in H. Finally, we give a characterization of isometric daisy graphs of a Hamming graph Kk1 · · · Kkn with respect to 0n in terms of an expansion procedure.Technical University Press20232024-04-10 03:45:47Članek v reviji88118sl