Dimitri Yafaev

Abstract:   The first part of the talk is an overview of basic notions of scattering theory. This theory studies two different but intimately related problems: large time behavior of solutions of the Schrödinger equation and unitary equivalence of quantum Hamiltonians. One of the main objects of scattering theory is the scatterig matrix (SM) which relates directly the asymptotic behavior of a quantum system as the time t does to plus or minus infinity, avoiding a study of this system for finite times. (SM is a unitary operator in L² over the unit sphere.) In the second part of the talk, spectral properties of SM as well as singularities of its kernel (if SM is regarded as integral operator) are discussed.

Here are some directions to Northeastern University. Lake Hall and Nightingale Hall can be best accessed from the entrance on the corner of Greenleaf Street and Leon Street. The two halls are connected, with no well-defined boundary in between. In particular, 509 Lake Hall is on the same corridor as 544 Nightingale Hall.

There is free parking available for people coming to the Colloquium at Northeastern's visitor parking (Rennaisance Garage). The entrance is from Columbus Avenue. If coming by car, you should park there and take the parking talon. After the lecture, you may pick up the payment coupon from Maxim Braverman.