Spring 2026

Oscar Blasco (University of Valencia): Annihilating pairs of sets for the uncertainty principle

Abstract: The heuristic uncertainty principle establishes that it is not possible for both a function and its Fourier transform to be localized on "small" sets.
Let E and F be a pair of measurable sets on Euclidean space. The pair (E,F) is said to be annihilating if a function f in L^2 vanishes as soon as f is supported in E and its Fourier transform f^ is supported in F. The aim of the talk is to give some historical survey of several results on different conditions to obtain annihilating pairs and also its connection with the study of the compactness of the operator P_EQ_F acting on L^2 where P_E f stands for the restriction of f to the set E and Q_F f corresponds to the functions whose Fourier transform is the f^ restricted to F.


Maxim Derevyagin (University of Connecticut):

Abstract: To be announced.


Lars Becker (Princeton University): Quantitative pointwise convergence of non-conventional ergodic averages

Abstract: Birkhoff's classical pointwise ergodic theorem states that the time-averages of a function f of a dynamical system converge pointwise as the time tends to infinity. Bourgain extended this result to so-called non-conventional ergodic averages, which capture the double recurrence statistics of the system. This talk is about an optimal quantitative version of Bourgain's result: How many jumps larger than some threshold epsilon can the sequence of non-conventional averages have, before it eventually converges? This is joint work with Polona Durcik.

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This colloquium is coordinated by: Daniel Glasscock, Amanda Redlich, Joris Roos, Bobbie Wu