Holonomy Constraints in Double Holography and the Nature of Semi-Classical Gravity

by Dominik Neuenfeld

Friday 10 Sept 2021, 15:00 → 17:00 Europe/Zurich

Zoom only (CERN)

I discuss the relation between the d-dimensional BCFT and CFT+gravity
descriptions of double holography. In both descriptions entropies can
be computed using the RT formula in a (d+1)-dimensional bulk. I point
out that standard assumptions about entanglement wedge reconstruction
suggest that the homology condition for RT surfaces depends on which
of the boundary formulations is taken. It then follows that the von
Neumann entropy of a subregion in the BCFT is computed by using the
island formula in the CFT+gravity description. Vice-versa, the von
Neumann entropy of bath subregions in the CFT+gravity description is a
coarse-grained entropy in the BCFT formulation. I also briefly discuss
how operators map between both boundary descriptions. Simple bath
operators are identical in both descriptions while some complicated
operators in the BCFT map to local operators in the island. It is then
tempting to speculate about implications for the relation between
semi-classical and quantum gravity in d>2.