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Friday, November 8, 2024 - 4:00pm

Yiannis Sakellaridis

JHU

Location

University of Pennsylvania

Towne 303

The Riemann zeta function was introduced by Euler, but carries Riemann's name because he was the one who extended it to a meromorphic function on the entire complex plane, and discovered its importance for the distribution of primes. It admits a vast class of generalizations, called L-functions, but, as in Riemann's case, one usually cannot prove anything about them without relying on seemingly unrelated integral representations.
 
In joint work with David Ben-Zvi and Akshay Venkatesh, we elucidate the origin of such integral representations, showing that they are manifestations of a duality between nice Hamiltonian spaces for a pair $(G,\check G)$ of ``Langlands dual'' groups. Over the geometric cousins of number fields -- algebraic curves and Riemann surfaces -- such dualities had been anticipated and constructed in many cases by Gaiotto and others, motivated by mathematical physics. 
 
 In the second talk, I will introduce a conjectural duality between nice (``hyperspherical'') Hamiltonian spaces, and how it gives rise to a hierarchy of conjectures, both function- and sheaf-theoretic, refining the Langlands correspondence.