Coherent potential approximation, averaged T-matrix approximation and Lloyd's model

It is shown how the single-site coherent potential approximation and the averaged T-matrix approximation become exact in the calculation of the averaged single-particle Green function of the electron in the Anderson model when the site energy is distributed randomly with lorentzian distribution. Using these approximations, Lloyd's exact result is reproduced.

Miniversal Deformations Of Dialgebras

We develop the theory of versal deformations of dialgebras and describe a method for constructing a miniversal deformation of a dialgebra.