2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/149116$M$-dimensional extended objects $Σ$ can be described by projecting a Diff $Σ$ invariant Hamiltonian of time-independent Hamiltonian density {\cal H} onto the Diff $Σ$- singlet sector, which after Hamiltonian reduction, using {\cal H} itself for one of the gauge-fixing conditions, results in a non-local description that may enable one to extend the non-local symmetries for strings to higher dimensions and make contact with gravity at an early stage.9 pages, Plain TeX, YITP/K-1079 unreadable character codes are correctedHigh Energy Physics - Theorytext