Seminarium Fizyki Materii Skondensowanej

The parquet equations provide a framework for self-consistent determination of the self-energy and the vertex corrections. In the context of many-body theory they were first introduced by de Dominicis and Martin alredy in the 1960th. However, the computational effort needed for two-particle self-consistent calculations limited their use only to impurity models or implied applying strong approximations to the equations. Recent advances in computational infrastructure make now calculations for lattice models feasible.In the talk I will shortly introduce parquet decomposition of two-particle vertex functions and the various approximations made to the irreducible vertices which are input to the parquet equations. I will also present preliminary results obtained with the our new implementation for the 2D Hubbard model on a square lattice in the so-called parquet approximation and within the dynamical vertex approximation scheme.