Space-time uncertainty principle and conformal symmetry in D-particle dynamics

Motivated by the space-time uncertainty principle, we establish a conformal symmetry in the dynamics of D-particles. The conformal symmetry, combined with the supersymmetric nonrenormalization theorem, uniquely determines the classical form of the effective action for a probe D-particle in the backg round of a heavy D-particle source, previously constructed by Becker-Becker -Polchinski-Tseytlin. Our results strengthen the conjecture proposed by Mal dacena on the correspondence, in the case of D-particles, between the super gravity and the supersymmetric Yang-Mills matrix models in the large-N limi t, the latter being the boundary conformal field theory of the former in th e classical D-particle background in the near-horizon limit. (C) 1998 Elsev ier Science B.V.