2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/17039The thermodynamics of a long self-repulsive chain is studied. In $D<4$ dimensions it shows two distinctly different regimes, corresponding to weak and strong correlations in the system. A simple microscopic analytical model is presented which successfully describes both the regimes. The self-consistent scheme is used, in which the center of mass of a chain is fixed explicitly. This allows to take correlations into account in an indirect manner.9 pages, 3 figuresStatistical Mechanicstext