Infrared Behavior of Interacting Bosons at Zero Temperature

C. Castellani; C. Di Castro; F. Pistolesi; G. C. Strinati

doi:10.1103/physrevlett.78.1612

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Infrared Behavior of Interacting Bosons at Zero Temperature

C. Castellani·C. Di Castro·F. Pistolesi·G. C. Strinati

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Abstract

We exploit the symmetries associated with the stability of the superfluid phase to solve the long-standing problem of interacting bosons in the presence of a condensate at zero temperature. Implementation of these symmetries poses strong conditions on the renormalizations that heal the singularities of perturbation theory. The renormalized theory gives: For d>3 the Bogoliubov quasiparticles as an exact result; for 1<d<=3 a nontrivial solution with the exact exponent for the singular longitudinal correlation function, with phonons again as low-lying excitations.

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C. Castellani, C. Di Castro, F. Pistolesi, G. C. Strinati. 1997-03-10. Infrared Behavior of Interacting Bosons at Zero Temperature. https://doi.org/10.1103/physrevlett.78.1612

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