Yasuaki Hikida

We study properties of heavy-light-heavy three-point functions in two-dimensional conformal field theories by using the modular invariance of two-point functions on a torus. We show that the result is nontrivially consistent with the condition of eigenstate thermalization hypothesis. We also study the open-closed duality of cylinder amplitudes and derive behaviors of disk one-point functions.

In this Letter, we propose a holographic duality for classical gravity on a three-dimensional de Sitter space. We first show that a pair of SU(2) Chern-Simons gauge theories reproduces the classical partition function of Einstein gravity on a Euclidean de Sitter space, namely S^{3}, when we take the limit where the level k approaches -2. This implies that the conformal field theory (CFT) dual of gravity on a de Sitter space at the leading semiclassical order is given by an SU(2) Wess-Zumino-Witt

A bstract We present a class of dS/CFT correspondence between two-dimensional CFTs and three-dimensional de Sitter spaces. We argue that such a CFT includes an SU(2) WZW model in the critical level limit k → − 2, which corresponds to the classical gravity limit. We can generalize this dS/CFT by considering the SU( N ) WZW model in the critical level limit k → −N , dual to the higher-spin gravity on a three-dimensional de Sitter space. We confirm that under this proposed duality the classical par

We compute the conformal blocks of the Virasoro minimal model or its ${\mathrm{W}}_{N}$ extension with large central charge from Wilson line networks in a Chern-Simons theory including loop corrections. In our previous work, we offered a prescription to regularize divergences from loops attached to Wilson lines. In this paper, we generalize our method with the prescription by dealing with more general operators for $N=3$ and apply it to the identity ${\mathrm{W}}_{3}$ block. We further compute g

We study D-branes in the Lorentzian AdS 3 background from the viewpoint of boundary states, emphasizing the role of open-closed duality in string theory. Employing the world sheet with Lorentzian signature, we construct the Cardy states with the discrete series. We show that they are compatible with (1) unitarity and normalizability, and (2) the spectral flow symmetry, in the open string spectrum. We also discuss their brane interpretation. We further show that in the case of superstrings on AdS

We study the correlators of the 2D W N minimal model in the semiclassical regime with large central charge from the bulk viewpoint by utilizing open Wilson lines in sl(N ) Chern-Simons gauge theory. We extend previous works

A bstract We analyze the asymptotic symmetry of higher spin gravity with M × M matrix valued fields, which is given by rectangular W-algebras with su( M ) symmetry. The matrix valued extension is expected to be useful for the relation between higher spin gravity and string theory. With the truncation of spin as s = 2, 3,…, n , we evaluate the central charge c of the algebra and the level k of the affine currents with finite c , k . For the simplest case with n = 2, we obtain the operator product

We investigate the $SL(2,\mathbb{R})/U(1)$ WZW model with level $0<k<2$ as a solvable time-dependent background in string theory. This model is expected to be dual to the one describing a rolling closed string tachyon with a timelike linear dilaton. We examine its exact metric and minisuperspace wave functions. Two point functions and the one-loop vacuum amplitude are computed and their relation to the closed string emission is discussed. Comparing with the results from the minisuperspace

Recently, a 2d coset model with $$ \mathcal{N}=3 $$ superconformal symmetry was pro-posed to be holographic dual to a higher spin supergravity on AdS3 and the relation to superstring theory was discussed. However, away from the tensionless limit, there is no higher spin symmetry and the higher spin states are massive. In this paper, we examine the deformations of the coset model which preserve $$ \mathcal{N}=3 $$ superconformal symmetry, but break generic higher spin symmetry. We focus on double