Boundary Conditions at the Mobility Edge

Abstract
It is shown that the universal behavior of the spacing distribution of nearest energy levels at the metal-insulator Anderson transition is indeed dependent on the boundary conditions. The spectral rigidity Σ2(E) also depends on the boundary conditions, but this dependence vanishes at high energy E. This implies that the multifractal exponent D2 of the participation ratio of wave functions in the bulk is not affected by the boundary conditions.