Hugh P Kelly, 3 September 1931 – 29 June 1992

Abstract

It is said that Racah was one of the few physicists who was able not only to read Hermann Weyl's book “The Theory of Groups and Quantum Mechanics” but also to understand enough to use it himself. Something similar applies to Hugh Kelly, who introduced the methods of Many-Body Perturbation Theory (MBPT), which was being developed by nuclear physicists like Keith Brueckner whom Hugh worked with as a post-doc, into atomic physics. Since atomic physics with its “known” forces is a perfect area in which to apply the methods of MBPT, it is clear that this would have happened sooner or later. Hugh Kelly's achievement is that it happened very early. Hugh's death this summer after a long battle with cancer is a great loss to atomic physics and to his many friends in the community.Hugh P Kelly got his PhD from the University of California at Berkeley in 1963 under the supervision of Kenneth Watson and in 1965 he was hired as assistant Professor at the University of Virginia. His appointment was to a large extent due to the support of M E Rose, also a nuclear physicist with interest in atoms as is clear from his book “Elementary Theory of Angular Momentum”. Hugh remained at the University of Virginia for the rest of his life, over the years serving as Department Chairman, Faculty Dean and, during the last years, as University Provost, but throughout Hugh pursued his real passion which was Physics. It is a clear sign of his dedication that he is sole author on a large number of papers particularly of course in the early years when he alone was Atomic Theory in Charlottesville.Hugh contributed to many areas of atomic physics although early on photoionization became his favourite subject and the one where he made his main contribution: first for closed shell atoms, but later extending his techniques to open shell systems for which the normal MBPT techniques did not apply.Hugh had a good nose for finding projects that were of topical interest and many of his papers are concerned with the controversies of the day although it is often difficult to see this from the way the papers have been written up. This does not mean that he did not have strong opinions about the correct interpretation of a particular phenomenon. When I expressed my frustration to him about colleagues who would not see the errors of their ways, Hugh would answer “It will all come out in the wash” and I guess he was usually right, even though I have often wished for some stronger washing powder.To recall meetings with Hugh is to remember the innocent sweetness of his smile and his unfailing good humour. The ICAP conference in Göteborg took place during a heat wave and the last evening, Hugh, Knut Fægri from Norway, who worked with Hugh for a while, and I decided to go swimming. We were told about a place which could be reached by public transport and went there only to find out that the bathing spot was located in a military zone from which foreigners were prohibited. It was fairly difficult to make Hugh understand that Swedish neutrality was, at least in principle, as much directed against NATO as against the usual enemy. Kelly had served in the US Marines and, although the only really positive remark I heard from him on this subject concerned the pension it had provided him with, we decided to take advantage of his experience and have our swim. The main part of the “plan” was his promise not to answer questions or otherwise talk during the mission while we would try to provide some half-authentic Swedish in an emergency. The foray was accomplished in high spirits, but it is only fair to mention that the Swedes did in fact take Hugh's breach of their neutrality so lightly that he was given an honorary degree by the University of Göteborg a few years later.Hugh Kelly continued to work until his last days, and publications are still appearing from his hand. The only positive thing I can find in his untimely death is that he has shown how we can face our own end with dignity. I will never forget him.