현승준 교수

We study the AdS-CFT correspondence in the case of ${\mathrm{AdS}}_{3}.$ We obtain the statistical entropy of the BTZ black hole in terms of the correct central charge and the conformal dimensions for the states corresponding to the BTZ black hole. We point out the difference between our method and the old fashioned approaches based on the $\mathrm{SL}(2,R)$ Wess-Zumino-Witten model or Liouville theory.

We construct IIA GS superstring action on the ten-dimensional pp-wave background, which arises as the compactification of eleven-dimensional pp-wave geometry along the isometry direction. The background geometry has 24 Killing spinors and among them, 16 components correspond to the non-linearly realized kinematical supersymmetry in the string action. The remaining eight components are linearly realized and shown to be independent of x^+ coordinate, which is identified with the world-sheet time c

We construct a quasilocal formalism for conserved charges in a theory of gravity in the presence of matter fields that may have slow falloff behaviors at the asymptotic infinity. This construction depends only on equations of motion, and so it is irrespective of ambiguities in the total derivatives of the Lagrangian. By using identically conserved currents, we show that this formalism leads to the same expressions of conserved charges as those in the covariant phase space approach. At the bounda

We work out boundary conditions for the covariant open string in the type IIA plane wave background, which corresponds to the D-branes in the type IIA theory. We use the kappa symmetric string action and see what kind of boundary conditions should be imposed to retain kappa symmetry. We find half BPS as well as quarter BPS branes and the analysis agrees with the previous work in the light cone gauge if the result is available. Finally we find that D0-brane is non-supersymmetric.

Certain nonasymptotically flat but supersymmetric classical solutions of type IIA supergravity can be interpreted as the infinitely boosted version of the $D$ particle solution along the $M$-theory circle. By a chain of $T$-dual transformations, this analysis also applies to yield nonasymptotically flat solutions from the asymptotically flat and (non)extremal solutions with intersecting $D$ strings and $D$ five-branes of type IIB supergravity compactified on a five-torus. Under $S$ duality, the

The effective action for the membrane dynamics on the background geometry of the $N$-sector discrete light-cone quantization (DLCQ) M theory compactified on a two-torus is computed via supergravity. We compare it to the effective action obtained from the matrix theory, i.e., the $(2+1)$-dimensional supersymmetric Yang-Mills (SYM) theory, including the one-loop perturbative and full nonperturbative instanton effects. Consistent with the DLCQ prescription of M theory in the manner of Susskind, we

We continue to explore the scaling transformation in the reduced action formalism of gravity models. As an extension of our construction, we consider the extended forms of the Smarr relation for various black holes, adopting the cosmological constant as the bulk pressure as in some literatures on black holes. Firstly, by using the quasi-local formalism for charges, we show that, in a general theory of gravity, the volume in the black hole thermodynamics could be defined as the thermodynamic conj

Via supergravity, we argue that the infinite Lorentz boost along the M theory circle in the manner of Seiberg toward the DLCQ M theory compactified on a $p$-torus $(p<5)$ implies the holographic description of the microscopic theory. This argument lets us identify the background geometries of DLCQ M theory on a $p$-torus; for $p=0(p=1),$ the background geometry turns out to be eleven-dimensional (ten-dimensional) flat Minkowski space-time, respectively. Holography for these cases results from