Norman Lebovitz, UChicago mathematician who unraveled the behaviors of stars and galaxies, 1935-2022

Norman Lebovitz, a professor emeritus of mathematics at the University of Chicago who taught for more than 40 years and worked to unravel the complex behaviors of stars and galaxies, died Dec. 28, 2022. He was 87.

Born Sept. 27, 1935, Lebovitz grew up in Los Angeles and earned his BA from UCLA in 1956. He received his PhD in physics from the University of Chicago in 1961. His doctoral advisor was the famed astrophysicist Subrahmanyan Chandrasekhar, with whom he would continue to collaborate for decades.

Lebovitz joined the faculty of the University of Chicago in 1963 as a founding member of the Applied Mathematics Program, which he chaired for many years.

Though a mathematician, Lebovitz was interested in math as a way to understand the rules of the universe around us. In particular, he conducted mathematical analysis of the equilibrium and stability of rotating self-gravitating fluids that provide simple models of planets and stars. He worked closely with Chandrasekhar on “Ellipsoidal Figures of Equilibrium,” a treatise on rotating liquid masses published in 1969, and became known as the world's expert on self-gravitating rotating fluid objects.

Lebovitz worked on applications of the virial theorem for astrophysics, dynamical systems, differential equations, asymptotics, and Hamiltonian methods. Later in his career, he also became interested in the perturbations in flowing fluids that lead to turbulence.

“His science was like him—very careful, very methodical, very clean,” said Phil Morrison, a professor of physics at the University of Austin-Texas and a colleague, collaborator, and close friend. “His writing is clear and concise, and devoid of any grandiose claims or salesmanship. Because of this his papers are a delight to read, and you can rely on every word being correct.”

Lebovitz published more than 70 scientific papers and edited two books during his career. He also published a free online textbook on differential equations.

His colleagues spoke of him as a “gentle human being and a gifted scientist”—a quiet but kind presence who was always willing to help those who approached with questions about mathematics.

Joseph Biello, professor of mathematics at University of California, Davis and a longtime friend, described his first encounters with Lebovitz: “I was an eager and imprecise young physics graduate student. Professor Lebovitz was a deliberate, patient, and clear mathematician. I was reluctant to be slowed down; but listening to him I understood the demands of precision and care while crafting arguments,” Biello recalled. “Through the course of that friendship I came to learn about his kindness, his open heartedness, his care for students, his unconditional love for his family, and his generous guidance of young faculty. I will be forever grateful that he took me under his wing.”

Lebovitz was a fellow of the Alfred P. Sloan Foundation from 1967-69 and the John Simon Guggenheim Foundation from 1977-78. From 1983-1988 he was the managing editor of SIAM Journal on Applied Mathematics. In 2012, he was elected as a fellow of the American Physical Society for “fundamental work on the fluid mechanics of rotating stars and self-gravitating masses, and for the development and use of mathematical methods applied to problems of geophysical and astrophysical fluid dynamics.”

Starting in 1985, he was deeply involved in the Summer Program on Geophysical Fluid Dynamics at the Woods Hole Oceanographic Institution located on Cape Cod, Mass., where he enjoyed spending summers with his friends and colleagues.

He retired in 2002, but continued to teach undergraduate classes in differential equations, and to publish academic papers.

In addition to his scholarly pursuits, he was a great lover of tennis, mystery novels, Roman history and Humphrey Bogart movies, his family said.

He lived the last 20 years of his life in New Buffalo with his wife Ruth, who survives him. He is also survived by sons David (wife Chongting) and Michael (wife Anna) and grandchildren Isaac, Cyrus, Esther, and Katherine. In keeping with his wishes, there is no memorial planned.