English

Extracting Edge Modes: Reduction of 3D and 2D Gravities

High Energy Physics - Theory 2025-12-24 v1

Abstract

We investigate the boundary reduction of 3D Einstein gravity and JT gravity into their respective edge mode theories - namely, the Liouville and Alekseev-Shatashvili, and Schwarzian models. By examining the roles of boundary conditions, canonical transformations, and differing formulations - metric versus Chern-Simons - we clarify how physical degrees of freedom become localized at the boundary and resolve several long-standing ambiguities in the reduction procedure.

Keywords

Cite

@article{arxiv.2509.09239,
  title  = {Extracting Edge Modes: Reduction of 3D and 2D Gravities},
  author = {Euihun Joung and Sejin Kim},
  journal= {arXiv preprint arXiv:2509.09239},
  year   = {2025}
}

Comments

6 pages