We present a self-contained study of ADHM multi-instantons in SU(N) gauge t
heory, especially the novel interplay with supersymmetry and the large-N li
mit. We give both field- and string-theoretic derivations of the N = 4 supe
rsymmetric multi-instanton action and collective coordinate integration mea
sure. As a central application, we focus on certain n-point functions G(n),
n = 16, 8 or 4, in N = 4 SU(N) gauge theory at the conformal point (as wel
l as on related higher-partial-wave correlators); these are correlators in
which the 16 exact supersymmetric and superconformal fermion zero-modes are
saturated. In the large-hr limit, for the first time in any four-dimension
al theory, we are able to evaluate all leading-order multi-instanton contri
butions exactly. We find compelling evidence for Maldacena's conjecture: (1
) The large-N k-instanton collective coordinate space has the geometry of a
single copy of AdS(5) x S-5, (2) The integration measure on this space inc
ludes the partition function of ten-dimensional N = 1 SU(k) gauge theory di
mensionally reduced to zero dimensions, matching the description of D-insta
ntons in Type IIB string theory. (3) In exact agreement with Spe IIB string
calculations, at the k-instanton level, G(n) = root N g(8) k(n-7/2) e(2 pi
ik tau) Sigma(d/k) d(-2) . F-n(x(1)...,x(n)), where F-n is identical to a
convolution of n bulk-to-boundary supergravity propagators. (C) 1999 Publis
hed by Elsevier Science B.V. All rights reserved.