Holographic probes of anti-de Sitter spacetimes - art. no. 104021

We describe probes of anti-de Sitter spacetimes in terms of conformal field theories on the AdS boundary. Our basic tool is a formula that relates bul k and boundary states-classical bulk field configurations are dual to expec tation values of operators on the boundary. At the quantum level we relate the operator expansions of bulk and boundary fields. Using our methods, we discuss the CFT description of local bulk probes including normalizable wav e packets, fundamental and D-strings, and D-instantons. Radial motions of p robes in the bulk spacetime are related to motions in scale on the boundary , demonstrating a scale-radius duality. We discuss the implications of thes e results for the holographic description of black hole horizons in the bou ndary field theory. [S0556-2821(99)03808-4].