Extremal graphs with respect to two distance-based topological indices?

The eccentric distance sum and degree distance have been well-studied in the past several years. More recently, many authors have considered the relationships between several distance-based graph invariants. Hua et al. (2018) investigated the relationship between the eccentric distance sum and the degree distance. In this paper, we present upper and lower bounds on ??d(G) ??? D???(G) among all connected graphs. The sharp lower and upper bounds on ??d(G)???D???(G) of general graphs with given connectivity (resp. edge number, number of cut edges, and matching number) are determined. In addition, we characterize the extremal graphs attaining those bounds. ?? 2022 Elsevier B.V. All rights reserved.