Mathematical Physics and Harmonic Analysis Seminar 21 September 2007, Bloc 627 Title: A Szego-type Theorem for Finite-Gap Jacobi Matrices Speaker: Maxim Zinchenko, CalTech Abstract: In this talk I will present some recent results on perturbations of almost-periodic Jacobi matrices with a finite number of gaps in the spectrum. In particular, I will discuss a Szego-type theorem which provides a description of all Jacobi matrices with spectral measures satisfying a Szego-type condition. I will also address a limit almost periodic behavior of coefficients for such Jacobi matrices. This talk is based on joint work in progress with Jacob Christiansen and Barry Simon.