# Quantum Entanglement Entropy in String Theory

- Institution: CERN
- Department: Conferences, Workshops & Schools
- Speaker: Atish Dabholkar
- Year: 2024
- Language: English
- Subjects: Physics
- Source: [CERN](https://videos.cern.ch/record/3011454)
- Licence: [CERN](http://copyright.web.cern.ch)
- Who can watch: Tweens profiles and older (sources give no ratings; placed by Invisible Network from the source's own words)

I discuss physical motivations from black hole physics and holography for expecting finite quantum entanglement entropy in quantum gravity. I describe recent and earlier results in defining such a notion in perturbative string theory by a stringy analog of the replica method using ZN orbifolds constructed for any odd positive integer N. The entropy so defined naturally includes a classical piece and is manifestly UV finite but has potential tachyonic IR divergences. I show that for several string compactifications as well as on black hole horizons in AdS3/CFT2 holography, the specific structure of the tachyonic spectrum allows for a re-summation and analytic continuation to the physical region 0 < N ≤ 1 where the IR divergences are absent and the resulting entropy is finite to one-loop order..

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## Lectures

1. [Quantum Entanglement Entropy in String Theory](https://invisiblenetwork.ai/learn/cern/3011454/b799612f8c44), 33 min (CERN's player)