%0 Journal Article
%T Bloch invariants of hyperbolic 3-manifolds
%A Walter D. Neumann
%A Jun Yang
%J Mathematics
%D 1997
%I arXiv
%X 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).
%U http://arxiv.org/abs/math/9712224v1