Speaker
Description
Conventional implementations of the functional renormalization group (fRG) rely on regulators for bare propagators only, notably in the framework of the Wetterich equation. Starting from Schwinger-Dyson and Bethe-Salpeter equations, we develop an fRG formulation where both bare propagators and bare interactions can be dressed with regulators. This makes the resulting fRG setup more flexible, allowing the implementation of approaches that are inaccessible to conventional fRG schemes. An example is the realization of temperature flows (which are commonly used to treat many-electron systems) for models with electron-phonon couplings.
In this talk, I will explain that this fRG formulation, based on regulators for bare interactions, is a generalization of the multiloop fRG, which has been shown to provide quantitatively accurate results for 2D lattice systems (beyond the conventional one-loop fRG derived from the Wetterich equation). The merits of a bosonization scheme called the single-boson exchange (SBE) decomposition will also be highlighted along the way. Finally, concrete applications will be presented for impurity models.
| Affiliation | Max Planck Institute for Solid State Research, Stuttgart |
|---|---|
| Link to paper | https://link.aps.org/doi/10.1103/7y6x-p6zx |
| Career status | Postdoc |