Birkhoff Conjecture for convex planar billiards and deformational spectral rigidity of planar domains

Birkhoff Conjecture for convex planar billiards and deformational spectral rigidity of planar domains

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Vadim Kaloshin, University of Maryland
Fine Hall 110

Please note special time and location.   The classical Birkhoff conjecture states that the only integrable convex planar domains are circles and ellipses. In a joint work with A. Avila and J. De Simoi we show that this conjecture is true for perturbations of ellipses of small eccentricity. It turns out that the method of proof gives an insight into deformational spectral rigidity of planar axis symmetric domains and gives a partial answer to a question of P. Sarnak. The latter is a joint work with J. De Simoi and Q. Wei.