The non-orientable spacetime of the eternal black hole

TL;DR

This paper explores a non-orientable spacetime geometry of the BTZ black hole by interchanging space and time characteristics, deriving dual thermofield double states for interior and exterior regions, and analyzing their implications for the bulk partition function.

Contribution

It introduces a novel non-orientable spacetime model of the BTZ black hole and constructs dual thermofield double states for both interior and exterior geometries.

Findings

Derived the metric for a non-orientable BTZ black hole.

Identified dual thermofield double states for interior and exterior regions.

Evaluated the bulk partition function for the non-orientable spacetime.

Abstract

We derive the metric of the BTZ black hole for the special case of interchanging the characteristics of space and time coordinates. We maximally extend the geometry of this interior solution and show that the line element is similar to its exterior solution counterpart. Thus, we assign the thermofield double state dual to this interior geometric construction. As a result, we have two independent thermofield double states corresponding to the BTZ metric: one dual to the exterior solution and one dual to the interior solution. In this scenario, considering both thermofield double states as dual to the full BTZ black hole, we evaluate the partition function of the bulk. The partition function represents a non-orientable spacetime. Additionally, we derive a thermofield double-like state that connects in the gravity dual the regions of spacetime with opposite orientations of space and time.