English

The Dehn-Nielsen-Baer Theorem for Bounded Surfaces

Geometric Topology 2026-04-22 v1

Abstract

Let Σ\Sigma be a bounded surface. We prove the Dehn-Nielsen-Baer theorem for bounded surfaces to show that the mapping class group of Σ\Sigma is isomorphic to the automorphisms of the fundamental groupoid of Σ\Sigma that fix loops around the boundary.

Keywords

Cite

@article{arxiv.2604.18815,
  title  = {The Dehn-Nielsen-Baer Theorem for Bounded Surfaces},
  author = {Elysia Wang},
  journal= {arXiv preprint arXiv:2604.18815},
  year   = {2026}
}

Comments

13 pages, 5 figures, comments welcome!

R2 v1 2026-07-01T12:27:10.631Z