Ilya Piatetski-Shapiro, a renowned scientist-refusenik from the Soviet Union who was professor emeritus and senior research scientist in mathematics at Yale, died on Feb. 22, in Tel Aviv, Israel, after a long debilitating illness. He was 79.
During a career that spanned 60 years, Piatetski-Shapiro made major contributions to applied science as well as theoretical mathematics. These contributions range from cell biology, geophysics, automata, and homogeneous networks, to digital computers. In the last 40 years his research focused on pure mathematics; in particular, analytic number theory, group representations and algebraic geometry. His main contribution and impact was in the area of automorphic forms and L-functions.
He was the recipient of many prizes, including the Wolf Prize - performing high-level research until the end of his life in spite of a deteriorating condition that left him severely handicapped and often deprived him of speech. Even when he could barely move, he traveled the world, attending conferences in order to exchange thoughts with colleagues about their latest researches.
Piatetski-Shapiro was born March 30, 1929, in Moscow, Russia. Both of his parents were from traditional Jewish families. In 1952, while still an undergraduate at Moscow University, Piatetski-Shapiro won the Moscow Mathematical Society Prize for a Young Mathematician. His winning paper contained a solution to the problem of the French analyst Raphael Salem on sets of uniqueness of trigonometric series.
Piatetski-Shapiro said he was surprised by the award, which was announced one week before Stalin's death, because of the surge in anti-Jewish activities sanctioned by the authorities at that time. Indeed, his application to enter a graduate program at Moscow University was rejected by the University Communist Party Committee, despite a very strong recommendation by his mentor Alexander O. Gelfond, who was a professor of mathematics at Moscow University and a prestigious party member. It was only by Gelfond's persistence that Piatetski-Shapiro was ultimately admitted to the Moscow Pedagogical Institute, where he received his Ph.D. He also attended seminars at the Steklov Institute, which awarded the more prestigious degree of Doctor of Sciences in 1954.
Piatetski-Shapiro's contact with Igor Shaferevic, who was a professor at the Steklov Institute, broadened his mathematical outlook and directed his attention to modern number theory and algebraic geometry. This eventually led to a joint paper on algebraic surfaces that has influenced many mathematicians. Piatetski-Shapiro also was influenced greatly by Israel M. Gelfand.
In 1958 Piatetski-Shapiro became professor of mathematics at the Moscow Institute of Applied Mathematics. By the 1960s he was recognized as a Soviet star. In 1965 he was appointed to an additional professorship at Moscow State University. His reputation spread internationally; in 1964 and 1968, he was invited to address the quadrennial International Mathematical Congresses.
Among his most important works were his collaborative efforts with Gelfand. Their aim was to introduce novel representation theory into classical modular forms and number theory.
In the 1970s, there was a growing emigration of Soviet Jews to Israel. In 1973, Piatetski-Shapiro arranged for his wife and son to leave Russia. The result was that he was fired from his Moscow State University professorship. In 1974, he applied for an exit visa to Israel.
As a refusenik, he lost access to mathematical libraries and other academic resources. He continued his researches nevertheless, and colleagues took books from the library for him. His plight as a mathematician, with such restrictions on his researches, attracted much attention in the United States. In 1976, a presentation was made to the Council of the National Academy of Sciences urging the use of its influence to get Piatetski-Shapiro an exit visa. Later that year, Piatetski-Shapiro obtained an exit visa and accepted a professorship at Tel Aviv University.
Starting in 1977, Piatetski-Shapiro divided his time between Tel-Aviv University and Yale, directing doctoral dissertations in both places. One of his major works at Yale dealt with the "Converse Theorem," which establishes a key link between automorphic forms on n by n matrix groups and zeta functions. The theorem has played a crucial role in many of the most striking results known towards the "principle of functoriality" of Langlands, which is considered the "holy grail" of modern number theory.
In later years James Cogdell, one of the mathematician's students who collaborated with him on the "Converse Theorem," was the only person outside Piatetski-Shapiro's immediate family who could understand his speech, and the Yale professor continued to work with Cogdell until 2009.
Piatetski-Shapiro is survived by his wife, Edith; his children, Gregory, Niki and Shelly; and his grandchildren, Peter and Matthew. He was buried in Israel on Feb. 24.