English

Bloch invariants of hyperbolic 3-manifolds

Geometric Topology 2007-05-23 v1

Abstract

We define an invariant \beta(M) of a finite volume hyperbolic 3-manifold M in the Bloch group B(C) and show it is determined by the simplex parameters of any degree one ideal triangulation of M. \beta(M) lies in a subgroup of \B(\C) of finite \Q-rank determined by the invariant trace field of M. Moreover, the Chern-Simons invariant of M is determined modulo rationals by \beta(M). This leads to a simplicial formula and rationality results for the Chern Simons invariant which appear elsewhere. Generalizations of \beta(M) are also described, as well as several interesting examples. An appendix describes a scissors congruence interpretation of B(C).

Keywords

Cite

@article{arxiv.math/9712224,
  title  = {Bloch invariants of hyperbolic 3-manifolds},
  author = {Walter D. Neumann and Jun Yang},
  journal= {arXiv preprint arXiv:math/9712224},
  year   = {2007}
}

Comments

25 pages. A slightly revised version will appear in Duke Math. J.