Jim Simons, Renaissance Man and Stalwart IAS Ally, Dies at 86

James H. Simons, a prize-winning mathematician, singular hedge fund manager, and a visionary philanthropist—with an indefatigable curiosity for science and discovery—died on Friday, May 10. He was 86.

With his wife Marilyn, Jim was a steadfast friend and patron of the Institute for Advanced Study. He was committed to connecting international communities of scholars and building bridges among disciplines, such as with The Simons Center for Systems Biology, which conducts research at the interface of biology and the physical sciences.

“Jim’s work shaped the Institute and its inhabitants in countless ways,” David Nirenberg, IAS Director and Leon Levy Professor, wrote on Friday in a message to the Institute community. “His mathematics animated and still animates the insights of many of our Faculty and Members in the School of Mathematics and the School of Natural Sciences. And as philanthropists, his and Marilyn’s work transformed the possibilities of existence for the Institute and for many other organizations dedicated to discovery," Nirenberg said. "Their philanthropy continues to nourish us in many ways (including quite literally, in the dining hall that bears their name).”

Jim provided distinguished counsel to the Board of Trustees for seventeen years—as Vice Chair from 2010 to 2018, and serving 14 years as Chair of the Investment Committee. During this time, Jim worked with three Institute Directors: Phillip A. Griffiths, Peter Goddard, and Robbert Dijkgraaf.

When Jim became Trustee Emeritus in 2018, the Board expressed in a resounding resolution of gratitude and admiration: “Through his passion for and support of innovation and ingenuity, Jim is a beacon, reminding us in real terms of the rewards of following one’s curiosity and deepest inquiries.”

“He was an important leader at the Institute,” said Edward Witten, Professor Emeritus in the School of Natural Sciences. “He had a passion for advancing research, especially in math and physics.”

Simons’s results in differential geometry—specifically the Chern-Simons functional (with frequent Institute Member Shiing-Shen Chern)—was highly influential in physics broadly, and personally to Witten’s work on knot theory. 

“He was always excited about new discoveries, always asking a lot of questions,” said Witten. “Even if the detailed understanding required more physics than he could understand, he was always interested to learn something about it.”

“He was always asking about why, for example, the Feynman path integral in quantum field theory is set up the way it is, with the exponential of the square root of minus one times the classical action,” Witten said. “That’s important input to understanding the role of the Chern-Simons function in many applications."

“Jim was one of the distinguished mathematicians who became fascinated by physics as a result of being surprised, probably, that some of the work he did was used by physicists,” Witten said.

Camillo De Lellis, IBM von Neumann Professor in the School of Mathematics, eventually came to know Simons as a maximal element in the Institute community and beyond, but for the longest time he knew the man only by his legendary 1968 paper on higher dimensional minimal surfaces (which De Lellis had practically memorized). It was a “foundational work and it triggered a paradigm shift,” De Lellis said—“it was a game changer in the field.”

When Ingrid Daubechies, an applied mathematician at Duke University and former President of the International Mathematical Union, proposed to Simons the idea of an interdisciplinary institute bringing together the talents of creative computational scientists from several fields, he immediately recognized the potential of the opportunity. Daubechies, a past Member (1999) in the School of Mathematics, recalled, “Jim said, ‘You know, I think this could work!’” The result is the Flatiron Institute in New York, conducting computationally driven research into astrophysics, biology, mathematics, neuroscience, and quantum chemistry. “It’s a fantastically collaborative environment,” said Daubechies, who is currently the Visiting Professor for the Public Dissemination of Mathematics at the National Museum of Mathematics in New York (MoMath; also funded by the Simons Foundation).

Simons received his doctorate from the University of California, Berkeley, in 1961 at age 23. In 1972, he was a Member of the Institute’s School of Mathematics. Following a stint in code making and breaking, he chaired—and transformed—the math department at Stony Brook University. In 1978, he founded what would ultimately become Renaissance Technologies, one of world’s most successful hedge funds. In 1994, Jim and Marilyn established the Simons Foundation, with the stated mission of “advancing the frontiers of research in mathematics and the basic sciences.” All the while, Simons continued his pursuit of mathematics. In 2007, with frequent IAS Visitor Dennis Sullivan of Stony Brook, he published “Axiomatic Characterization of Ordinary Differential Cohomology.” 

“It’s very hard to explain,” Simons told a New York Times reporter (after a few attempts). “But we solved it.” 

Sullivan recalled that during their multi-year weekly collaboration on mathematics, “I had the impression he was working at several times the volume of a normal schedule.” As a philanthropist, in particular, Simons devoted a lot of personal time and diligence. “Besides ‘writing checks,’ Jim worked hard to ensure that the supported enterprise had a better chance to flourish and perform its commission or purpose,” said Sullivan.

“His real talent, besides being a brilliant mathematician and having a sense of the market, was that he had a way of getting people to work together to build things—he was always building things. This requires not only being charming and funny and wise, but also attention to detail and non-trivial work. In the case I knew best, the Simons Center for Geometry and Physics (SCGP) at Stony Brook, he attended every board meeting, did his homework and contributed careful thinking.” For instance, Sullivan said, during construction of the SCGP building and plans for an outdoor garden, “I observed Jim negotiating the contractor’s bid down from $300,000 to $200,000.” 

In 1976, Simons received the Oswald Veblen Prize in Geometry—named for the founding IAS professor—from the American Mathematical Society. He was a Member of the American Academy of Arts and Sciences, the American Philosophical Society, and the National Academy of Sciences. On March 14, 2019, he was recognized during the inaugural IAS Einstein Gala with the IAS Bamberger Medal for his extraordinary service on the Institute’s Board of Trustees, his visionary support of the Institute’s mission, and his deep awareness of the essential need for basic research across the sciences and humanities. The event was commemorated with a tribute video.

John A. Overdeck, a philanthropist, Co-Founder of Two Sigma Investments, and the Chair of the IAS Board of Trustees, first intersected with Simons early in life. “As a child who loved numbers, I grew up listening to my father, a cryptographer, recount stories about a remarkable mathematician who left cryptography, and later academia, to found a finance company known for beating the market,” Overdeck recalled. “The mere possibility inspired me.” 

“As I started my career, I learned more about Jim Simons and his journey, and became increasingly intrigued by his accomplishments and the company he founded,” he said. “His dedication to philanthropy, specifically in support of research, autism, and STEM education, left a lasting impression on me. His passing is a tremendous loss, but his legacy of generosity and mentorship will remain with us.”