ABSORPTION BY BRANES AND SCHWINGER TERMS IN THE WORLD VOLUME THEORY

We study how coincident Dirichlet 3-branes absorb incident gravitons p olarized along their world volume. We show that the absorption cross-s ection is determined by the central term in the correlator of two stre ss-energy tensors. The existence of a non-renormalization theorem for this central charge in four-dimensional N = 4 supersymmetric Yang-Mill s theories shows that the leading term at low energies in the absorpti on cross-section is not renormalized. This guarantees that the agreeme nt of the cross-section with semiclassical supergravity, found in earl ier work, survives all loop corrections. The connection between absorp tion of gravitons polarized along the brane and Schwinger terms in the stress-energy correlators of the world volume theory holds in general . We explore this connection to deduce some properties of the stress-e nergy tensor OPE's for 2-branes and 5-branes in 11 dimensions, as well as for 5-branes in 10 dimensions. (C) 1997 Elsevier Science B.V.