Behaviour of the wave function near the origin in the radial case
  We give one more proof in two and three space dimensions that the irregular solution of the Schrodinger equation, for zero angular momentum, is in fact the solution of an equation containing an extra 'delta function'. We propose another criterium to eliminate the irregular solution which is to require the validity of the virial theorem of which we give a general proof in the classical and quantum cases. 
Andre Martin