2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/94951A suitable splitting of tachyon field equation is able to disclose non trivial properties of Born-Infeld (some known, some unexpected) and Polyakov actions; the tachyon equation also can be analyzed in some detail. The analysis displays an intriguing connection between sine-Gordon theory and some crucial issues such as the emergence of perturbative string states when a D-Brane and an anti-D-Brane annihilate and the confinement of charged D-Branes.11 pages, no figures, to be published on Physics Letters BGeneral Relativity and Quantum CosmologyHigh Energy Physics - Theorytext