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 ...

Two computer scientists found — in the unlikeliest of places — just the idea they needed to make a big leap in graph theory. This past October, as Jacob Holm and Eva Rotenberg were thumbing through a ...

Here’s a scary scenario: You’ve been put in charge of air traffic control at Newark airport near New York. You need to make sure every plane can taxi between the runway and its gate without hitting ...