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 ...

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 ...

Fifty years ago, Paul Erdős and two other mathematicians came up with a graph theory problem that they thought they might solve on the spot. A team of mathematicians has finally settled it. In the ...