James Vickers is an Emeritus Professor of Mathematics at the University of Southampton and has published extensively on general relativity. His early research was on the structure of weak singularities in relativity and more recently he has given proofs of both the Penrose and Hawking singularity theorems for low-regularity spacetimes. These show that the singularities predicted by these theorems must be accompanied by unbounded curvature. He has also worked on the asymptotic structure of space-time and used spinors to prove the positivity of the Bondi mass.