Few-Body Systems

, Volume 51, Issue 2–4, pp 153–180 | Cite as

Efimov Physics from the Functional Renormalization Group

  • Stefan FloerchingerEmail author
  • Sergej Moroz
  • Richard Schmidt


Few-body physics related to the Efimov effect is discussed using the functional renormalization group method. After a short review of renormalization in its modern formulation we apply this formalism to the description of scattering and bound states in few-body systems of identical bosons and distinguishable fermions with two and three components. The Efimov effect leads to a limit cycle in the renormalization group flow. Recently measured three-body loss rates in an ultracold Fermi gas of 6Li atoms are explained within this framework. We also discuss briefly the relation to the many-body physics of the BCS–BEC crossover for two-component fermions and the formation of a trion phase for the case of three species.


Renormalization Group Yukawa Coupling Trion Derivative Expansion Feshbach Resonance 
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Copyright information

© Springer-Verlag 2011

Authors and Affiliations

  • Stefan Floerchinger
    • 1
    • 2
    Email author
  • Sergej Moroz
    • 1
  • Richard Schmidt
    • 3
  1. 1.Institut für Theoretische PhysikHeidelbergGermany
  2. 2.Physics DepartmentTheory Unit, CERNGeneva 23Switzerland
  3. 3.Physik DepartmentTechnische Universität MünchenGarchingGermany

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