PROFESSOR VIJAY PANDHARIPANDE, 1940-2006

Gordon Baym

George and Ann Fisher Distinguished Professor of Engineering and

Center for Advanced Study Professor of Physics
University of Illinois, Urbana

Christopher Pethick
Professor, Nordita, Copenhagen, Denmark

Professor Vijay Pandharipande of the University of Illinois in Urbana, one of the leading nuclear theorists of his generation, died on January 3 of this year at the age of 65. Although he courageously fought a lung cancer, his strength eventually gave out.

For three decades Pandharipande developed and improved new methods for solving the quantum many-body problem, both analytically and through advanced many-body numerical techniques, such as Green's function Monte Carlo. The variational methods he developed in Copenhagen in 1970 started a revolution of which he remained the leader. The startling simplicity of his ideas profoundly affected the field of nuclear matter and overturned the generally accepted views of the time. The influence of his research extended well beyond nuclear physics, to condensed matter, astrophysics, and atomic physics.

Thanks to Pandharipande, we now have a firm quantitative theoretical path from the measured forces between nucleons to the properties of nuclei and nuclear and neutron star matter. With coworkers and students he carried out essentially exact calculations of the structure -- size, binding energies, and internal momentum distributions -- of light nuclei, up to 16 nucleons. Extending exact techniques well beyond the limits of Faddeev methods, he was the first to provide clear evidence for three-body forces in nuclei. His seminal calculations of uniform nuclear matter provide the basis for our present understanding of the structure and mass limits of neutron stars, as well as unusual components in neutron star matter such as hyperons, meson condensates, and quark droplets. A more recent theme of his research was unravelling the many-body physics of very strongly interacting trapped boson and fermion atomic systems.

His research also had major impact on the course of experimental studies of nuclear structure via precision high energy electron scattering, for which he was awarded the 1999 Tom W. Bonner Prize of the American Physical Society. He was a Fellow of the APS, and a Life Member of the Indian Physical Society. At the time of his death, he had just completed a major book -- to be published shortly -- which spells out his unique perspective on the many-body theory of nuclei. He was also one of the principal scientific advisors in nuclear physics, serving on the advisory committees of the Elba International Physics Center, the MIT Bates Accelerator Laboratory, NIKHEF-K in Amsterdam, the Continuous Beam Electron Accelerator at the Jefferson Laboratory, and the National Institute for Nuclear Theory in Seattle, chairing its advisory committee for a period; he generously served as well on the National Academy of Sciences--National Research Council Committee on Nuclear Physics and the Board of the European Institute for Nuclear Theory (ECT*) in Trento. He was also a long-term consultant at the Argonne National Laboratory.

Pandharipande single-handedly shaped a whole new generation of nuclear theorists, including some twenty Ph.D. students and a large number of postdocs and other scientific collaborators, who through his magnetic personality, have remained a closely knit international scientific family.

Born August 7, 1940 in Nagpur, India, he received his B.Sc. in 1959, and M.Sc. in 1961 from Nagpur University. He was a Research Assistant in experimental nuclear physics at the Tata Institute from 1961 to 1973, receiving his Ph.D. from Bombay University in 1969, and making the transition to theoretical physics at about this time. His talents soon came to the attention of Hans Bethe at Cornell University, and his international career was launched. He was a Fellow at the Niels Bohr Institute in Copenhagen from 1970 to 1971, a Postdoctoral Fellow at Cornell in 1972, and then came to the University of Illinois in Urbana in 1973, where he taught for the remainder of his life, rising eventually to the distinguished position of Center for Advanced Study Professor of Physics and Willet Professor of Engineering.

He is survived by his wife, Rajeshwari V. Pandharipande, Professor of Linguistics, Religious Studies, and Comparative literature at the University of Illinois, a son, Rahul V. Pandharipande, Professor of Mathematics at Princeton University, a daughter Pari V. Pandharipande, an M.D. in radiology at Massachusetts General Hospital and Harvard Medical School, and three grandchildren.

Vijay Pandharipande will be remembered as an independent and adventurous scientific giant; he will also be remembered for his warm personality and infectious laugh, and his love of life beyond physics, from cultivating peppers to being with and taking care of his family, both immediate and scientific, and friends.