Narahari Umanath Prabhu, a professor emeritus who helped make Cornell’s School of Operations Research and Information Engineering (ORIE) truly international, died at his home in Ithaca on Oct. 14. He was 98.

Known to most as Uma, Prabhu was born in Calicut (now Kozhikode), India, in 1924 and earned his B.A. in mathematics at Loyola College in Madras, India, an M.A. in statistics from the University of Bombay and an M.S. in mathematics from the University of Manchester in England – all at the top of his class.

Prabhu joined the ORIE faculty in 1965 at the age of 41. He had been living in Perth, Australia, and teaching at the University of Western Australia, when a book he wrote, “Stochastic Processes: Basic Theory and Its Applications,” found its way to Frank Spitzer, the late Cornell mathematics professor. Spitzer was greatly impressed by the book and gave it a rave review. The two men started writing to each other and eventually Spitzer recommended Prabhu for a job teaching at Cornell in what was then called the Department of Industrial Engineering. The two remained close friends until Spitzer’s death in 1992.

Prabhu’s work focused on stochastic processes and queueing theory and he co-founded the journal Stochastic Processes and Their Applications, which he co-edited from 1973 to 1984. He was also editor of the Queueing Systems Journal from 1986 to 1994.

In addition to his research, Prabhu was well-known for his love of and dedication to teaching. Student evaluations from his days in the classroom attest to his rigorous but supportive teaching style. His family members said that he considered his students his “spiritual children.”

Prabhu was a prolific letter writer and contacted mathematicians and researchers across the globe to ask questions and discuss ideas. Many of these researchers then sent their students to Ithaca to study with Prabhu at Cornell. In this way, he expanded the diversity of the school and helped strengthen its international reputation.

Professor Gennady Samorodnitsky joined the ORIE faculty in 1988, when Prabhu had already been at the school for 23 years.

“Uma came to the school of ORIE when it was very young, and he was one of the people who made this school what it is today: one of the leading departments anywhere in the world,” Samorodnitsky said. “He loved the school and was a mentor to many of the junior faculty members well before a position of a mentor came into existence. The school, Cornell and the science of applied probability have lost a great colleague and a great friend.”

Prabhu retired from teaching in 1994 but remained committed to the Cornell and Ithaca communities. In retirement, Prabhu continued to play an active role in the life of the school. Mark Lewis, director of ORIE, recalled meeting Prabhu during Lewis’s first days on campus in 2005.

“Of course, I knew of Uma Prabhu before I arrived here in 2005, but he was one of the first people to come into my office in my first week to welcome me,” Lewis said. “We talked about teaching, the importance of the student experience and not surprisingly, queueing. He left me with a copy of his book, which I promptly asked him to sign. He was a star academic, and an even kinder person.”

In 1999, Prabhu and his wife Sumi created the Rabindranath Tagore Lecture Series in South Asian Literature. The series brings international authors to Ithaca each year for readings and discussions which are free and open to the public. In 2018 Prabhu made a gift to establish the Frank Spitzer and Narahari Umanath Prabhu Assistant Professorship of Mathematics in honor of his longtime friend.

Prabhu was preceded in death by Sumi, his wife of 66 years. He is survived by his daughter Vasundhara Prabhu (“Vas”) and her husband Bob; his daughter Purnima Prabhu; and his granddaughters Basyah and Aliyah Prabhu.

Chris Dawson is brand manager and a writer for the College of Engineering.