title: Duality between the weak and strong interaction limits for randomly interacting fermions.
abstract: We establish the existence of a duality transformation for generic models of interacting fermions with two-body interactions. The eigenstates at weak and strong interaction U possess similar statistical properties when expressed in the U=0 and U= infinity eigenstates bases, respectively. This implies the existence of a duality point U(d) where the eigenstates have the same spreading in both bases. U(d) is surrounded by an interval of finite width which is characterized by a non-Lorentzian spreading of the strength function in both bases. Scaling arguments predict the survival of this intermediate regime as the number of particles is increased.
authors.affiliation: Instituut-Lorentz, Universiteit Leiden, P.O. Box 9506, 2300 RA Leiden, The Netherlands.
authors.forename: Philippe
authors.initials: P
authors.lastname: Jacquod
authors.forename: Imre
authors.initials: I
authors.lastname: Varga