Geoffrey Grimmett is Professor of Mathematical Statistics at the University of Cambridge and Master of Downing College, Cambridge. His research interests lie in disordered physical systems, including percolation and related processes. He has written numerous research articles in probability theory and statistical mechanics, as well as three research books and two successful textbooks on probability and random processes at the ... Read moreundergraduate and postgraduate levels. Dominic Welsh is Professor Emeritus of Mathematics at the University of Oxford and Emeritus fellow of Merton College, Oxford. He held the John von Neumann Professorship at Bonn in 1990-91, and was appointed Professor of Mathematics at Oxford in 1993. His research interests include combinatorics and complexity theory, and he has written more than a hundred papers in these areas. He retired from Oxford University in 2005, and has since then held visiting positions in New Zealand and Barcelona. Show Less