Variational and Parquet-diagram theory for strongly correlated normal and superfluid systems

Path integral variational methods for strongly correlated systems.

We introduce a new approach to highly correlated systems which generalizes the Fermi Hypernetted Chain and Correlated Basis Function techniques. While the latter approaches can only be applied to systems for which a non-relativistic wave function can be defined, the new approach is based on the variation of a trial hamiltonian within a path integral framework and thus can also be applied to rel...

Dynamical Variational Principles for Strongly Correlated Electron Systems

The self-energy-functional approach (SFA) is discussed in the context of different variational principles for strongly correlated electron systems. Formal analogies between static and dynamical variational approaches, different types of approximation strategies and the relations to density-functional and dynamical mean-field theory are emphasized. The discussion elucidates the strengths of the ...

Theory of the orbital Kondo effect with assisted hopping in strongly correlated electron systems: Parquet equations, superconductivity, and mass enhancement.

Orbital Kondo effect is treated in a model, where additional to the conduction band there are localized orbitals close to the Fermi energy. If the hopping between the conduction band and the localized heavy orbitals depends on the occupation of the atomic orbitals in the conduction band then orbital Kondo correlation occurs. The noncommutative nature of the coupling required for 1 the Kondo eff...

Unified theory of strongly correlated electron systems

In framework of eigen-functional bosonization method, we introduce an imaginary phase field to uniquely represent electron correlation, and demonstrate that the Landau Fermi liquid theory and the Tomonaga-Luttinger liquid theory can be unified. It is very clear in this framework that the TomonagaLuttinger liquid behavior of one-dimensional interacting electron gases originates from their Fermi ...

Bosonization and Strongly Correlated Systems