Construction of quantum gravity theory from superstring theory

点击翻译按钮获取中文摘要

(1)Yoneya investigated the space-time formulation of the AdS/CFT correspondence, in particular, in the so-called BMN limit. By studying the large R-charge limit of the previously conjectured relation known as the GKPW relation between the gauge-theory con-elation functions and the bulk partition functions of supergravity/string theory, he proposed a concrete relation between the 3-point vertex of light-cone string field theory and the gauge theory 3-point functions for the first time. He showed that the proposed relation is valid at least to first non-trivial approximations with respect to the string coupling constant for wide lass of non BPS operators. He also applied the same method to investigate 1/2 BPS correlators and Wilson loop expectation values with local operator insertions. As a new project, he initiated an exploration toward a quantum field theory of D-branes. After some preliminary study of the 1/2 BPS operators, he proposed a new framework for achieving this in the case o … More f D0-branes.(2)Kazama investigated the pure spinor (PS) formalism, a new promising super-covariant formulation of the superstring theory, and obtained the following results. (i) He proposed a novel extension of the PS formulation and showed its quantum equivalence with the existing formalisms. (ii)He constructed for the first time the fundamental worldsheet action from which the PS formalism can be derived from the first principle. He also succeeded in formulating the superstring theory in the plane-wave background with the Ramond-Ramond flux as a quantum conformal field theory.(3)Kato proposed new covariant gauges in string field theory, which correspond to a generalization of the covariant gauges in the ordinary gauge field theory including Landau gauge. Applying the gauge to the tachyon condensation, he obtained a smooth potential without a singularity which was gauge-artifact. Kato also studied a realization of lattice supersymmetry where he identified the symmetry of staggered fermion and showed the No-Go theorem for the Leibniz rule of the finite difference.(4) Hashimoto clarified the dynamics of D-branes which are non-perturbative objects in superstring theory. Our investigation has been mostly dedicated to relations between the D-branes and solitons in field theories. He succeded in exhibiting various properties of solitons. For example, he obtained nontrivial dynamics of instantons in Yang-Mills theories, monopoles and vortices, which had been very difficult to analyze in ordinary methods of field theories. In addition, we studied low energy dynamics of QCD using the D-brane method. Less