Zeeman Spectroscopy of the Star Algebra
  We solve the problem of finding all eigenvalues and eigenvectors of the Neumann matrix of the matter sector of open bosonic string field theory, including the zero modes, and switching on a background B-field. We give the discrete eigenvalues as roots of transcendental equations, and we give analytical expressions for all the eigenvectors. 
Bo Feng, Yang-Hui He and Nicolas Moeller