• openAccess   Analytic integrability of the Bianchi class A cosmological models with O~ 1< < 1 

      Ferragut, Antoni; Llibre, Jaume; Pantazi, Chara Elsevier (2013-03)
      Many works study the integrability of the Bianchi class A cosmologies with k = 1, where k is the ratio between the pressure and the energy density of the matter. Here we characterize the analytic integrability of the Bianchi ...
    • openAccess   Fractal generalized zone plates 

      Mendoza-Yero, Omel; Fernández Alonso, Mercedes; Mínguez-Vega, Gladys; Lancis, Jesús; Climent, Vicent; Monsoriu, Juan A. Optical Society of America (2009)
      The construction of fractal generalized zone plates (FraGZPs) from a set of periodic diffractive optical elements with circular symmetry is proposed. This allows us to increase the number of foci of a conventional fractal ...