• SIMPLE MODELS OF THREE COUPLED PT -SYMMETRIC WAVE GUIDES ALLOWING FOR THIRD-ORDER EXCEPTIONAL POINTS 

      Autor: Schnabel , Jan; Cartarius , Holger; Main , Jörg; Wunner , Günter; Heiss , Walter Dieter
      (České vysoké učení technické v PrazeCzech Technical University in Prague, 2017)
      We study theoretical models of three coupled wave guides with a PT-symmetric distribution of gain and loss. A realistic matrix model is developed in terms of a three-mode expansion. By comparing with a previously postulated ...
    • THE ANALYSIS OF IMAGES IN N-POINT GRAVITATIONAL LENS BY METHODS OF ALGEBRAIC GEOMETRY 

      Autor: Kotvytskiy , Albert; Bronza , Semen; Shablenko , Vladimir
      (České vysoké učení technické v PrazeCzech Technical University in Prague, 2017)
      This paper is devoted to the study of images in N-point gravitational lenses by methods of algebraic geometry. In the beginning, we carefully define images in algebraic terms. Based on the definition, we show that in this ...