Hale Freeman Trotter, emeritus professor of mathematics, died at his home in Princeton, New Jersey, on January 17 at the age of 91.

“Hale was dedicated to and valued education at all levels,” said Peter Cernak. Eugene Higgins Professor of Mathematics, Princeton University“His positive outlook inspired everyone at Fine Hall, from undergraduates to colleagues. He will be sorely missed.”
“Hale Trotter and I are great friends and as a colleague in the mathematics department, he was one of my favorites.
Born May 30, 1931 in Kingston, Ontario, Trotter graduated from Queen’s University with a degree in mathematics, graduating with a bachelor’s degree in 1952 and a master’s degree in 1953. A European intellectual who fled the Nazis and settled in the United States. Princeton attracted many of these refugees, including Albert Einstein, who had an office in the mathematics building (Jones Hall, then known as Fine Hall). It was in this rich and exciting atmosphere that Trotter matured as a mathematician.
after obtaining his Ph.D. In 1956, he began his career as an instructor of fine mathematics at Princeton University from his 1956 to his 1958. He then taught at Queen’s University from 1958 until 1960, when he returned to Princeton where he spent the rest of his career.
“When computerization first began many years ago, Hale was the first to return to Princeton to help the department adapt to the realities of computing,” said Hale, a graduate student at Princeton University for nearly half a century. Robert Gunning, a colleague in the mathematics department for many years, said: “He used computers more than many others in the department, and as a very active research mathematician, he had a real sense of what computerization meant to the running of the department. He was the first step, but others in the department followed up. ”
From 1979 to 1982, he served as Dean and from 1962 to 1986, Vice Director of the Data Center at Princeton University. He moved to his honorary position in 2000. His tenure as president was “marked by a high degree of composure and affability”.
““He was always a kind and helpful member of the math department, always willing to help, and a delightful friend with a very Canadian sense of humor,” said Gunning.
His colleague describes a beloved teacher teaching a wide range of mathematical concepts to both graduate and undergraduate students. Trotter also wrote several textbooks on higher-dimensional calculus.
“Hale’s work in various core areas of modern mathematics has resulted in a very wide-ranging influence,” says Sarnak. “he He was a pioneer and leader in the use of modern computers in pure mathematics. ”
He made significant contributions to group theory, knot theory, and number theory. His one of his outstanding achievements, the formula for the Trotter product, had a great impact on mathematical physics and functional analysis.
“As a physicist, I heard his name early in my career,” Reeve says, referring to the formula for the Trotter product as “Hail’s famous formula,” and “the most important to theoretical physics, which emerged from pure mathematics.” One that can be applied.”
Another powerful and useful tool he developed, the Johnson-Trotter Algorithm, is a technique for generating a complete list of highly significant permutations. He was also interested in knot theory and was the first to show that reversible pretzel knots exist, thereby solving a longstanding topology problem. Trotter later became interested in some of the computational aspects of number theory and developed the Lang-Trotter conjecture through collaboration with Yale mathematician Serge Lang.
He was survived by his beloved wife Kay, brother Bernard, and parents Reginald George Trotter and Prudence Trotter (née Fisher). He is survived by his stepson Stephen Parland (Rachel), his stepdaughter Nanette, grandson Eli and granddaughter Cora, sister-in-law Jean and brother-in-law John (Helen). Trotter was also great-uncle to Rex (Eliza) and Tory (Tibor Vaggy), great-uncle to John, Thomas (Stephanie), Andrew (Anne-Marie), Marie, Philip, Claire, Martin, and James. , Damian, Felix and Lily.
A memorial service will be held on Tuesday, May 31, at the Mother Hodge Funeral Home in Princeton from 3:00 to 5:00 pm, followed by an informal service at 4:00 pm. Salem, New York. In lieu of flowers, the family is asking for donations to the Kay and Hale Trotter Gynecologic Oncology Fund.
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