Correlated starting points for the functional renormalization group
arXiv:1411.1342 · doi:10.1103/PhysRevB.91.045120
Abstract
We present a general frame to extend functional renormalization group (fRG) based computational schemes by using an exactly solvable interacting reference problem as starting point for the RG flow. The systematic expansion around this solution accounts for a non-perturbative inclusion of correlations. Introducing auxiliary fermionic fields by means of a Hubbard-Stratonovich transformation, we derive the flow equations for the auxiliary fields and determine the relation to the conventional weak-coupling truncation of the hierarchy of flow equations. As a specific example we consider the dynamical mean-field theory (DMFT) solution as reference system, and discuss the relation to the recently introduced DMFRG and the dual-fermion formalism.
14 pages, 6 figures
References in corpus (10)
- Dynamical vertex approximation - a step beyond dynamical mean field theory
- Dual fermion approach to the two-dimensional Hubbard model: Antiferromagnetic fluctuations and Fermi arcs
- Dual Fermion Approach to Susceptibility of Correlated Lattice Fermions
- Non-perturbative renormalization-group approach to the Bose-Hubbard model
- Dynamical vertex approximation for nanoscopic systems
- Superperturbation solver for quantum impurity models
- Fermionic two-loop functional renormalization group for correlated fermions: Method and application to the attractive Hubbard model
- The two-loop functional renormalization-group approach to the one- and two-dimensional Hubbard model
- The effect of six-point one-particle reducible local interactions in the dual fermion approach
- An alternative functional renormalization group approach to the single impurity Anderson model