2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/27394It has recently been established that a short-range interaction can strongly delocalize a pair of particles moving in a disordered potential. We investigate whether an analogous effect exists also for pairs of quasiparticles in the Anderson insulator by employing an approximate numerical evaluation of the two-particle Green function of the many-body system. At the Fermi energy, the quasiparticle pair is localized on the scale of the single-particle localization length. The delocalization effect is recovered when the excitation energy of the pair is comparable to the bandwidth.4 pages and 3 figures in a uuencoded, compressed tar file; uses revtex and psfig.sty (included); to appear in Europhys. LettCondensed Mattertext