Wedge holography in flat space and celestial holography

In this paper, we study codimension two holography in flat spacetimes, based on the idea of wedge holography. We propose that a region $d+1$ dimensional spacetime surrounded by end world branes, which are given $d$ hyperbolic spaces, is dual to conformal field theory (CFT) $d\ensuremath{-}1$ sphere. Similarly, also bounded de Sitter spaces holographically CFT Our calculations partition function, holographic entanglement entropy and point functions, support these duality relations imply such CFTs nonunitary. Finally, glue dualities along null surfaces realize for full Minkowski discuss possible connection celestial