Nonperturbative Renormalisation Group: Applications to the few and many-body systems

We consider the applications of functional renormalisation group to few and many-body systems. As an application to the few-body dynamics we study the ratio between the fermion-fermion scattering length and the dimer-dimer scattering length for systems of few nonrelativistic fermions. We find a st...

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Bibliographic Details
Main Author: Krippa B.
Format: Article
Language:English
Published: EDP Sciences 2010-04-01
Series:EPJ Web of Conferences
Online Access:http://dx.doi.org/10.1051/epjconf/20100302003
Description
Summary:We consider the applications of functional renormalisation group to few and many-body systems. As an application to the few-body dynamics we study the ratio between the fermion-fermion scattering length and the dimer-dimer scattering length for systems of few nonrelativistic fermions. We find a strong dependence on the cutoff function used in the renormalisation flow for a two-body truncation of the action. Adding a simple threebody term substantially reduces this dependence. In the context of many-body physics we study the dynamics of both symmetric and asymmetric many-fermion systems using the same functional renormalisation technique. It is demonstrated that functional renormalisation group gives sensible and reliable results and provides a solid theoretical ground for the future studies. Open questions as well as lines of further developments are discussed.
ISSN:2100-014X