From hyperbolic Dehn filling to surgeries in representation varieties

Abstract

Hyperbolic Dehn surgery and the bending procedure provide two ways which can be used to describe hyperbolic deformations of a complete hyperbolic structure on a 3-manifold. Moreover, one can obtain examples of non-Haken manifolds without the use of Thurston's Uniformization Theorem. We review these gluing techniques and present a logical continuity between these ideas and gluing methods for Higgs bundles. We demonstrate how one can construct certain model objects in representation varieties $\text{Hom}\left({\pi }_1\left(\Sigma \right),G\right)$ for a topological surface $\Sigma$ and a semisimple Lie group $G$. Explicit examples are produced in the case of $\Theta$-positive representations lying in the smooth connected components of the $\text{SO}\left(p,p+1\right)$-representation variety.

arXiv comment56 pages; semi-expository article prepared for the book series "In the tradition of Thurston"