Quantum entanglement index in string theory
Abstract
A bstract We define a notion of ‘quantum entanglement index’ with the aim to compute it for black hole horizons in string theory at one-loop order using the stringy replica method. We consider the horizon of BTZ black holes to construct the relevant conical orbifolds, labeled by an odd integer N , and compute the partition function as a function of N , corresponding to the fractional indexed Rényi entropy. We show that it is free of tachyons and naturally finite both in the ultraviolet and the infrared, even though it is generically ultraviolet divergent in the field theory limit. Thus, the index provides a useful diagnostic of the entanglement structure of string theory without the need for analytic continuation in N .
Fields of Study & Subjects
Computational Physics and Python Applications
Relativity and Gravitational Theory
Publication details
- Journal / source
- Journal of High Energy Physics
- Publisher
- Springer Science and Business Media LLC
- Volume
- 2026
- Issue
- 2
- Publication date
- 12 February 2026
- Language
- EN