John Clive Ward. 1 August 1924—6 May 2000

Abstract

John Clive Ward was a theoretical physicist who made important contributions to two of the principal subjects in twentieth-century elementary particle physics: namely, quantum electrodynamics (QED) and electroweak theory. He was an early proponent of the importance of gauge theories in quantum field theory and their use in demonstrating the renormalization of those theories: that is, to remove apparent infinities in calculations. He showed that gauge invariance implies the equality of two seemingly different renormalized quantities in QED, a relationship now called the Ward Identity. This identity can be generalized to more general gauge theories in particle physics and remains a fundamental tool in these theories, which dominate particle theory at the present time. He collaborated with Abdus Salam on the use of gauge theories in strong interactions and in electroweak theory. He also made significant contributions to statistical physics. In 1955 he was recruited by the UK Atomic Weapons Research Establishment at Aldermaston to head the Green Granite section of the theoretical group, which had the task of rederiving the thermonuclear weapon concepts developed by Ulam and Teller in the United States. He spent the years from 1966 to his retirement in 1984 at Macquarie University in Australia.