On the CTMA and similar integral equations

For a strongly correlated electron lattice, if treated within dynamical mean-field theory, the most advanced analytical approach for the infinite U Anderson model as impurity solver is the consistent T-matrix approximation (CTMA). Recently [H. Keiter, K. Baumgartner, Phys. Staus Solidi B 242 (2005) 377.] we solved the central integral equations of the CTMA numerically with self-adaptive nets, and analytically with a new version of the slow variable approximation. Both methods were in very good agreement. Further progress on that problem is reported