Solving the Richardson equations close to the critical points
  We study the Richardson equations close to the critical values of the paring strength g_c where the occurrence of divergencies preclude numerical solutions. We derive a set of equations for determining the critical g values and the non-collapsing pair energies. Studying the behavior of the solutions close to the critical points, we develop a procedure to solve numerically the Richardson equations for arbitrary coupling strength. 
F. Dominguez, C. Esebbag and J. Dukelsky