https://doi.org/10.1051/epjconf/20100302003
Nonperturbative Renormalisation Group: Applications to the few and many-body systems
1
School of Physics and Astronomy, University of
Manchester, Manchester
M13 9PL,
UK
2
Institute for Theoretical and Experimental
Physics, 117259, Moscow, Russia
a e-mail: boris.krippa@manchester.ac.uk
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.
© Owned by the authors, published by EDP Sciences, 2010
