Functional renormalization group for two-body scattering

Cluster Functional Renormalization Group

Functional renormalization group (FRG) has become a diverse and powerful tool to derive effective low-energy scattering vertices of interacting many-body systems. Starting from a non-interacting expansion point of the action, the flow of the RG parameter Λ allows to trace the evolution of the effective one-particle and two-particle vertices towards low energies by taking into account the vertex...

Similarity Renormalization Group for Few-Body Systems

Internucleon interactions evolved via flow equations yield soft potentials that lead to rapid variational convergence in few-body systems. The Similarity Renormalization Group (SRG) [1, 2] provides a compelling method for evolving internucleon forces to softer forms by decoupling lowfrom high-momentum matrix elements [3, 4]. A series of unitary transformations parameterized by s (or λ ≡ s−1/4) ...

From infinite to two dimensions through the functional renormalization group.

We present a novel scheme for an unbiased, nonperturbative treatment of strongly correlated fermions. The proposed approach combines two of the most successful many-body methods, the dynamical mean field theory and the functional renormalization group. Physically, this allows for a systematic inclusion of nonlocal correlations via the functional renormalization group flow equations, after the l...

A NUMERICAL RENORMALIZATION GROUP APPROACH FOR AN ELECTRON-PHONON INTERACTION

A finite chain calculation in terms of Hubbard X-operators is explored by setting up a vibronic Harniltonian. The model conveniently transformed into a form so that in the case of strong coupling a numerical renormalization group approach is applicable. To test the technique, a one particle Green function is calculated for the model Harniltonian

Renormalization Group Renormalization Group