## SciPost Submission Page

# Near horizon dynamics of three dimensional black holes

### by Daniel Grumiller, Wout Merbis

#### - Published as SciPost Phys. 8, 010 (2020)

### Submission summary

As Contributors: | Daniel Grumiller |

Arxiv Link: | https://arxiv.org/abs/1906.10694v3 (pdf) |

Date accepted: | 2020-01-10 |

Date submitted: | 2019-09-27 |

Submitted by: | Grumiller, Daniel |

Submitted to: | SciPost Physics |

Discipline: | Physics |

Subject area: | High-Energy Physics - Theory |

Approach: | Theoretical |

### Abstract

We perform the Hamiltonian reduction of three dimensional Einstein gravity with negative cosmological constant under constraints imposed by near horizon boundary conditions. The theory reduces to a Floreanini-Jackiw type scalar field theory on the horizon, where the scalar zero modes capture the global black hole charges. The near horizon Hamiltonian is a total derivative term, which explains the softness of all oscillator modes of the scalar field. We find also a (Korteweg-de Vries) hierarchy of modified boundary conditions that we use to lift the degeneracy of the soft hair excitations on the horizon.

### Ontology / Topics

See full Ontology or Topics database.Published as SciPost Phys. 8, 010 (2020)

### List of changes

1. In the lines below (16) we have replaced the ... by arbitrary gauge parameters followed by the remark that these gauge parameters do not appear in the transformation law or in the charges.

2. Added a footnote in the first line of subsection 2.1.

3. The first two paragraphs of subsection 2.2 are new and replace/correct the previous first paragraph.

4. The last paragraph of subsection 2.3 is new.

5. Added third sentence in beginning of section 3.

6. Changed notation in and around Eqs. (62)-(63) from epsilon to xi to distinguish it from epsilon in other sections.

7. In sections 5 and 6 we changed to font for epsilon to distinguish it from epsilon in previous sections.

### Submission & Refereeing History

## Reports on this Submission

### Anonymous Report 1 on 2019-10-23 Invited Report

### Report

I recommend the revised manuscript to be published.