2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/55241An overview over effects of D-instantons in ten dimensional IIB superstring theory is given, including the supergravity instanton solution, instanton induced effective interaction vertices, the conjectured $SL(2,Z)$ invariant completion of such terms and the connection of such terms to a one loop calculation in eleven dimensional supergravity.14 pages, Latex, 1 figure, uses crckapb.sty, Talk given at the NATO-ASI on Strings, Branes and Dualities, Cargese, France, 1997High Energy Physics - Theorytext