ABSTRACT
This chapter argues that a similar claim of emergence, but using a different physical duality, namely, the holographic one, also called the anti-de Sitter (AdS)/conformal field theory (CFT) correspondence. Broadly speaking, the AdS/CFT duality shows the redundancy of any posit about fundamental geometry in string theory more radically than T-duality. The AdS/CFT is a duality between a string theory over an AdS spacetime and a CFT over its boundary. The two sides of the duality show theories positing not only geometrically and topologically inequivalent spacetimes but also incommensurably different physical ontologies. The original AdS/CFT correspondence was derived by combining two different descriptions of D-branes, one in terms of open strings and the other in terms of closed ones. In the case of holographic duality, nothing in its formal structure shows some trace of asymmetry. One element of the dual pair can be derived from the other and vice versa.
