$SU(2)$-representations of Branched Covers
Abstract
We study the existence of irreducible -representations for cyclic branched covers of knots in . Our main result establishes that if is a non-trivial prime knot and is an integer such that and is an integer homology sphere, then admits an irreducible -representation, whenever satisfies one of two conditions: either is -periodic, or can be represented as the closure of a tangle adapted to a SICUP matrix. The first condition leverages a commuting trick for covering spaces to realize higher-degree branched covers as 2-fold covers, allowing us to apply recent results of Kronheimer-Mrowka and others. The second condition uses equivariant surgery descriptions and the invariant from instanton Floer homology. As applications, we provide new infinite families of hyperbolic integer homology spheres admitting irreducible representations, including examples where previously known criteria fail.
Keywords
Cite
@article{arxiv.2508.19669,
title = {$SU(2)$-representations of Branched Covers},
author = {Sudipta Ghosh and Zhenkun Li and Juanita Pinzón-Caicedo},
journal= {arXiv preprint arXiv:2508.19669},
year = {2025}
}
Comments
21 pages, 7 figures, comments are welcome