### One-loop transition amplitudes in the D1D5 CFT

We consider the issue of thermalization in the D1D5 CFT. Thermalization is expected to correspond to the formation of a black hole in the dual gravity theory. We start from the orbifold point, where the theory is essentially free, and does not thermalize. In earlier work it was noted that there was no clear thermalization effect when the theory was deformed of the orbifold point to first order in the relevant twist perturbation. In this paper we consider the deformation to second order in the twist, where we do find effects that can cause thermalization of an initial perturbation. We consider a 1-loop process where two untwisted copies of the CFT are twisted to one copy and then again untwisted to two copies. We start with a single oscillator excitation on the initial CFT, and compute the effect of the two twists on this state. We find simple approximate expressions for the Bogoliubov coeffcients and the behavior of the single oscillator excitation in the continuum limit, where the mode numbers involved are taken to be much larger than unity. We also prove a number of useful relationships valid for processes with an arbitrary number of twist insertions.

- Publication Date:

- Grant/Contract Number:
- sc0011726

- Type:
- Accepted Manuscript

- Journal Name:
- Journal of High Energy Physics (Online)

- Additional Journal Information:
- Journal Name: Journal of High Energy Physics (Online); Journal Volume: 2017; Journal Issue: 1; Journal ID: ISSN 1029-8479

- Publisher:
- Springer Berlin

- Research Org:
- The Ohio State Univ., Columbus, OH (United States)

- Sponsoring Org:
- USDOE

- Country of Publication:
- United States

- Language:
- English

- Subject:
- 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; Conformal Field Models in String Theory; AdS-CFT Correspondence; Black Holes; Black Holes in String Theory

- OSTI Identifier:
- 1424736

```
Carson, Zaq, Hampton, Shaun, and Mathur, Samir D.
```*One-loop transition amplitudes in the D1D5 CFT*. United States: N. p.,
Web. doi:10.1007/JHEP01(2017)006.

```
Carson, Zaq, Hampton, Shaun, & Mathur, Samir D.
```*One-loop transition amplitudes in the D1D5 CFT*. United States. doi:10.1007/JHEP01(2017)006.

```
Carson, Zaq, Hampton, Shaun, and Mathur, Samir D. 2017.
"One-loop transition amplitudes in the D1D5 CFT". United States.
doi:10.1007/JHEP01(2017)006. https://www.osti.gov/servlets/purl/1424736.
```

```
@article{osti_1424736,
```

title = {One-loop transition amplitudes in the D1D5 CFT},

author = {Carson, Zaq and Hampton, Shaun and Mathur, Samir D.},

abstractNote = {We consider the issue of thermalization in the D1D5 CFT. Thermalization is expected to correspond to the formation of a black hole in the dual gravity theory. We start from the orbifold point, where the theory is essentially free, and does not thermalize. In earlier work it was noted that there was no clear thermalization effect when the theory was deformed of the orbifold point to first order in the relevant twist perturbation. In this paper we consider the deformation to second order in the twist, where we do find effects that can cause thermalization of an initial perturbation. We consider a 1-loop process where two untwisted copies of the CFT are twisted to one copy and then again untwisted to two copies. We start with a single oscillator excitation on the initial CFT, and compute the effect of the two twists on this state. We find simple approximate expressions for the Bogoliubov coeffcients and the behavior of the single oscillator excitation in the continuum limit, where the mode numbers involved are taken to be much larger than unity. We also prove a number of useful relationships valid for processes with an arbitrary number of twist insertions.},

doi = {10.1007/JHEP01(2017)006},

journal = {Journal of High Energy Physics (Online)},

number = 1,

volume = 2017,

place = {United States},

year = {2017},

month = {1}

}