Parametrization of spectral surfaces of a class of periodic 5-diagonal   matrices
  The main result of this work is a parametric description of the spectral surfaces of a class of periodic 5-diagonal matrices, related to the strong moment problem. This class is a self-adjoint twin of the class of CMV matrices. Jointly they form the simplest possible classes of 5-diagonal matrices. 
Ionela Moale and Peter Yuditskii
math.SP math.CV