Existence and role of higher-codimension replica fixed points in bulk RT derivations

Ascertain whether, in the bulk replica construction used to derive the Ryu–Takayanagi formula, the replica symmetry action can generically possess additional fixed points of codimension greater than two, and, if so, characterize their physical relevance and contributions to the gravitational action and entanglement entropy.

Background

The replica method in the bulk involves quotienting by a Zn symmetry, whose codimension‑two fixed set corresponds to the cosmic brane sourcing the conical defect. The standard derivation assumes the dominant singularities are codimension‑two.

The author raises the possibility of additional higher‑codimension fixed points under the replica symmetry. Understanding if and when such fixed points occur, and whether they affect the derivation or physical predictions, is an open issue.