Daniel S. Koltun, a professor emeritus of physics at the University of Rochester who made important contributions to the field of nuclear physics, died on April 9, 2014, in Haverford, Pa. He was 80.
Koltun joined the University in 1962 and was a professor of physics until his retirement in 2004. A theoretical physicist, Koltun's research interests and activities were largely focused on the study of nuclear structure and reactions at intermediate and high energy, as well as with many-body theory. He was interested in understanding the dynamics of nuclei as many-body systems, and the role of subnucleon constituents in this problem, including mesons – particularly pions – and quarks. In addition to being a leader in the meson physics community, Koltun was known for what is called the "Koltun Sum Rule" for the scattering of electrons from nuclear targets.
Long associated with the scientific program of the Los Alamos Meson Physics Facility, he was a visiting staff member there for 18 years and served on its Program Advisory Committee.
Koltun received an A.B. degree from Harvard University and earned his Ph.D. in physics from Princeton University. He was a visiting fellow at the Weizmann Institute of Science, Israel, and at the Niels Bohr Institute, Denmark. He was also a visiting professor at Tel Aviv University (1976-77), and at the Hebrew University Jerusalem (1985), both in Israel. He had been awarded an NSF Postdoctoral Fellowship, an Alfred P. Sloan Research Fellowship, and a John Simon Guggenheim Memorial Fellowship. He was a fellow of the American Physical Society.
Koltun was the coauthor, with the late Judah M. Eisenberg, of the books Theory of Meson Interactions with Nuclei (1980) and Quantum Mechanics of Many Degrees of Freedom (1988). He has also served as associate editor of the journals Physical Review C and Physical Review Letters.
He is survived by his wife of 57 years, Judith; two children, Naomi Koltun-Fromm (Ken Koltun-Fromm) and Joshua (Chau); four grandchildren, Ariel, Talia and Isaiah Koltun-Fromm and Mila Koltun; and two sisters, Victoria Kelman (Rabbi Stuart Kelman) and Elizabeth Koltun.
The University's flag will be flown at half-mast on Thursday, April 24, in his memory.