2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/55573Superstring theory, and a recent extension called M theory, are leading candidates for a quantum theory that unifies gravity with the other forces. As such, they are certainly not ordinary quantum field theories. However, recent duality conjectures suggest that a more complete definition of these theories can be provided by the large N limits of suitably chosen U(N) gauge theories associated to the asymptotic boundary of spacetime.14 pages, latex2e; Presented at WEIN 98 in Santa Fe, NM (June 1998); v2: Reference addedHigh Energy Physics - Theorytext