We consider chemical graphs that are defined as connected graphs of maximum degree at most 3. We characterize the extremal ones, that is, those that maximize...

The arithmetic-geometric index is a newly proposed degree-based graph invariant in mathematical chemistry. We give a sharp upper bound on the value of this ...

We investigate the ratio $\mathcal{I}(G)$ of the average size of a maximal matching to the size of a maximum matching in a graph G. If many maximal mat...

A coloring of a graph is an assignment of colors to its vertices such that adjacent vertices have different colors. Two colorings are equivalent if they indu...

We study the average number $A(G)$ of colors in the non-equivalent colorings of a graph $G$. We show some general properties of this graph invariant ...