TITLE: In Graph Theory, if $G$ is a graph, then what does $\Delta(G)$ mean?
QUESTION [7 upvotes]: I know that in Graph Theory, if we have a graph $G = (V, E)$, then $\delta(G)$ means the $\min d(v)$ over all $v\in V$, but what about $\Delta(G)$? What does it mean?

REPLY [10 votes]: Typically $\Delta$ is used to denote the maximum degree of $G$, i.e., the largest degree out of all of the degrees. To be absolutely sure, check the source you are reading. If it doesn't define it, assume this.