Geometric interpretation of simplicial formulas for the Chern-Simons invariant

Abstract

We give a direct interpretation of Neumann's combinatorial formula for the Chern-Simons invariant of a 3-manifold with a representation in PSL(2,C) whose restriction to the boundary takes values in upper triangular matrices. Our construction does not involve group homology or Bloch group but is based on the construction of an explicit flat connection for each tetrahedron of a simplicial decomposition of the manifold.

22 pages, 2 figures

References in corpus (3)

• Extended Bloch group and the Cheeger-Chern-Simons class
• Classical and quantum dilogarithmic invariants of flat PSL(2,C)-bundles over 3-manifolds
• A dilogarithmic formula for the Cheeger-Chern-Simons class

Cited by in corpus (2)

• Flat connections in three-manifolds and classical Chern-Simons invariant
• Cohomological invariants of representations of 3-manifold groups