2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/56053Instead of the infinitesimal extrinsic and intrinsic perturbations on strings, considered so far, we discuss the evolution and propagation of finite-amplitude perturbations. Those intrinsic perturbations may result in appearance of stable discontinuities similar to the shock waves.9 pages, LaTeXHigh Energy Physics - Theorytext