• Hölder Continuity of the Spectra for Aperiodic Hamiltonians 

      [OWP-2019-05] Beckus, Siegfried; Bellissard, Jean; Cornean, Horia (Mathematisches Forschungsinstitut Oberwolfach, 2019-02-26)
      We study the spectral location of a strongly pattern equivariant Hamiltonians arising through configurations on a colored lattice. Roughly speaking, two configurations are "close to each other" if, up to a translation, ...
    • Spectral Continuity for Aperiodic Quantum Systems II. Periodic Approximations in 1D 

      [OWP-2018-27] Beckus, Siegfried; Bellissard, Jean; De Nittis, Giuseppe (Mathematisches Forschungsinstitut Oberwolfach, 2018-12-17)
      The existence and construction of periodic approximations with convergent spectra is crucial in solid state physics for the spectral study of corresponding Schrödinger operators. In a forthcoming work [9] this task was ...
    • Spectral Regularity and Defects for the Kohmoto Model 

      [OWP-2025-05] Beckus, Siegfried; Bellissard, Jean; Thomas, Yannik (Mathematisches Forschungsinstitut Oberwolfach, 2025-04)
      We study the Kohmoto model including Sturmian Hamiltonians and the associated Kohmoto butterfly. We prove spectral estimates for the operators using Farey numbers. In addition, we determine the impurities at rational ...