2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/219424The formalism for computing the gravitational power radiation from excitations on cosmic strings forming a junction is presented and applied to the simple case of co-planar strings at a junction when the excitations are generated along one string leg. The effects of polarization of the excitations and of the back-reaction of the gravitational radiation on the small scale structure of the strings are studied.minor changes added, the published version in JCAPHigh Energy Physics - TheoryAstrophysicsGeneral Relativity and Quantum Cosmologytext