Graph theory may show how individuals are connected, for example, but not capture the ways in which clusters of friends on social media influence each other’s behavior.

The study of such graphs is called graph theory. Engineers need to find planarity in a graph when, for example, they are designing a computer chip without a crossed wire.

Refining with colors Mathematicians have developed various strategies to compare graphs. Since the 1970s, algorithms have been able to test graph isomorphism, but in exponential time.

Abstractions blog A New Algorithm for Graph Crossings, Hiding in Plain Sight Two computer scientists found — in the unlikeliest of places — just the idea they needed to make a big leap in graph theory ...

Graph theory has a lot to say about how phenomena can grow, such as the spread of infectious diseases. There are different graphs, or networks, of relations, and they can affect things such as the ...