English

Exact integral formulas for volumes of two-bridge knot cone-manifolds

Geometric Topology 2026-05-22 v2

Abstract

We provide exact integral formulas for hyperbolic and spherical volumes of cone-manifolds whose underlying space is the 33-sphere and whose singular set belongs to three infinite families of two-bridge knots: C(2n,2)C(2n,2) (twist knots), C(2n,3)C(2n,3), and C(2n,2n)C(2n,-2n) for any non-zero integer nn. Our formulas express volumes as integrals of explicit rational functions involving Chebyshev polynomials of the second kind, with integration limits determined by roots of algebraic equations. This extends previous work where only implicit formulas requiring numerical approximation were known.

Keywords

Cite

@article{arxiv.2510.02095,
  title  = {Exact integral formulas for volumes of two-bridge knot cone-manifolds},
  author = {Anh T. Tran and Nisha Yadav},
  journal= {arXiv preprint arXiv:2510.02095},
  year   = {2026}
}

Comments

Accepted for publication in Transformation Groups