• Generalizações do truque de Kotani 

      Monteiro, Wagner (Universidade Federal de São Carlos, UFSCar, Programa de Pós-Graduação em Matemática - PPGM, Câmpus São Carlos, 17/02/2016)
      We present a study of rank-one perturbations of self-adjoint and unitary operators, in particular related to the so-called Kotani’s trick. In Chapter 2 we recall relevant definitions and elementary facts. In Chapter 3 we ...
    • Perturbações unitárias multiplicativas 

      Díaz, Pablo (Universidade Federal de São Carlos, UFSCar, Programa de Pós-Graduação em Matemática - PPGM, Câmpus São Carlos, 24/05/2023)
      For the self-adjoint operator H, the perturbation H+A, with A also a self-adjoint operator, there is a long list of results regarding the spectrum of this perturbation. We study the spectrum of a multiplicative perturbation ...