Giant gravitons in AdS/CFT (I): matrix model and back reaction

In this article we study giant gravitons in the framework of AdS/CFTcorrespondence. First, we show how to describe these configurations in the CFTside using a matrix model. In this picture, giant gravitons are realized assingle excitations high above a Fermi sea, or as deep holes into it. Then, wegive a prescription to define quasi-classical states and we recover the knownclassical solution associated to the CFT dual of a giant graviton that grows inAdS. Second, we use the AdS/CFT dictionary to obtain the supergravity boundarystress tensor of a general state and to holographically reconstruct the bulkmetric, obtaining the back reaction of space-time. We find that the space-timeresponse to all the supersymmetric giant graviton states is of the same form,producing the singular BPS limit of the three charge Reissner-Nordstr\"om-AdSblack holes. While computing the boundary stress tensor, we comment on thefinite counterterm recently introduced by Liu and Sabra, and connect it to ascheme-dependent conformal anomaly.Comment: 28 pages, JHEP3 class. v2: typos corrected and references adde