Friends of IHES is delighted to welcome Vasily Pestun to its Board of Directors. A former Permanent Professor of Physics at IHES, Vasily now serves as a Research Scientist at Renaissance Technologies, an investment management firm founded by former Friends of IHES co-Chair Jim Simons. Vasily brings a wealth of experience in both academic research and applied science. Discover more about his background and his involvement with Friends of IHES below.

Vasily, you are a theoretical physicist by training and held a position as Permanent Professor of Physics at IHES for nearly a decade from 2014 to 2023. Can you tell us a bit about your background, your academic journey, and your time at IHES?

I was born in the Soviet Union shortly before its disintegration, a time marked by political and economic upheaval. Despite the chaos, certain schools maintained high standards, particularly in math and physics. I am especially grateful to the teachers of Saint Petersburg School 239, who nurtured my interest in these fields. As a child, I was fascinated by chemistry, astronomy, and programming, but physics always stood out to me as “the real thing,” with mathematics serving as its natural model.

For college, I attended the Moscow Institute of Physics and Technology (MIPT), often referred to as the “MIT of Russia.” One serendipitous moment occurred during my first summer there: amidst a pile of discarded books, I stumbled upon Superstring Theory by Michael B. Green, John H. Schwarz, and Edward Witten. Its promise to explain the “theory of everything” intrigued me, even though its contents were incomprehensible at first. Over time, I attended string theory seminars in Moscow, which deepened my fascination and ultimately led me to pursue a PhD at Princeton.

My years at Princeton were formative, offering me the opportunity to learn from luminaries like Edward Witten, Alexander Polyakov, and Nikita Nekrasov, who was also a Permanent Professor at IHES, and who is now a member of the Friends of IHES Honorary Committee. During this time, I tackled a longstanding problem in quantum field theory concerning loop operators in maximally supersymmetric Yang-Mills theory, leading to significant breakthroughs. This work later laid the foundation for many of my subsequent projects.

What are the first things that come to mind when you think about IHES? Are there any special memories you’d like to share?

IHES is an extraordinary place, and my years there remain deeply cherished. The setting itself – the peaceful garden that greets you at the entrance, the surrounding forest, and the tranquility of the village – creates a unique atmosphere conducive to deep, focused thought.

Some of my fondest memories include the daily lunches, shared with outstanding scientists, including Fields medalists and Abel Prize laureates, where conversations ranged from cutting-edge research to informal anecdotes. I also remember the iconic seminar room chalkboard, regularly filled with elegant mathematical equations and diagrams, and the legendary 4 p.m. tea sessions, where chance encounters with scholars like Pierre Cartier often led to fascinating discussions on topics as diverse as p-adic physics. Finally, the preserved schedule of Alexander Grothendieck’s algebraic geometry seminar, displayed in the IHES library, served as a constant reminder of the Institute’s rich history.

You have also spent significant time in the United States and are now working at Renaissance Technologies. How has this transition influenced your perspective on science, and science funding, and why do you believe private support is vital for basic research?

I spent 11 years in the US, working at Princeton, Harvard, and the Institute for Advanced Study. These institutions provided unparalleled opportunities to explore fundamental questions in theoretical physics. More recently, my interests have extended to computer-aided mathematics and machine learning, including projects like a joint IHES-IBM initiative on automated theorem proving.

At Renaissance Technologies, I’m part of a team dedicated to leveraging sophisticated algorithms to address inefficiencies in financial markets. Financial models are highly dynamic systems, blending numerical computation with human decision-making. This role has deepened my appreciation for the complex interplay between abstract theory and practical application.

Fundamental research often requires decades – or even centuries – before yielding tangible benefits, making it challenging to align with the short-term outlook of market-driven funding models. While public funding remains essential, it is often difficult to convince political leaders and taxpayers of the importance of investing in abstract science. This is where private philanthropy becomes crucial, acting as a bridge to ensure curiosity-driven research can continue.

One of the main reasons I joined Renaissance Technologies and moved to Stony Brook was to help channel market inefficiencies into funding for mathematics and science, notably following the footsteps of Jim Simons, whom I deeply admire. As a Member of the Board of Friends of IHES, I hope to contribute to that mission and support the long-term vitality of basic research.