Graph colouring, the assignment of colours to the vertices of a graph so that no two adjacent vertices share the same colour, represents a canonical NP-hard combinatorial optimisation problem with ...

For example, imagine you wanted to color each dot below so that there were never two dots of the same color next to each other—this is an example of coloring. Dr. Liu explains, "I work on a type of ...

A theorem for coloring a large class of “perfect” mathematical networks could ease the way for a long-sought general coloring proof. Four years ago, the mathematician Maria Chudnovsky faced an all-too ...