Three dimensional Janus and time-dependent black holes

TL;DR

The work extends the holographic Janus construction to AdS3×S3×M4, providing an explicit AdS2-sliced Janus solution in IIB supergravity and identifying its ICFT2 dual as the D1-D5 CFT with a spatially varying marginal dilaton operator. It additionally constructs time-dependent BTZ-type and higher-dimensional topological black holes within the Janus framework, yielding two-boundary geometries with differing boundary couplings and time-evolving horizons. These results offer a tractable platform for studying interface holography and nonstatic holography, including conformal perturbation theory checks and cosmological boundary scenarios. The solutions remain under analytic control and illustrate how dilaton warping interacts with holographic central charges and boundary dynamics across dimensions.

Abstract

We show that the three dimensional Janus geometry can be embedded into the type IIB supergravity and discuss its dual CFT description. We also find exact solutions of time dependent black holes with a nontrivial dilaton field in three and higher dimensions as an application of the Janus construction.

Figures (1)

• Figure 1: Penrose diagram for the time dependent black hole with two couplings. The $\tau$ ($\in [-\pi/2,\pi/2]$) coordinate runs vertically upward and $\mu$ ($\in [-\mu_0,\mu_0]$) to the right horizontally