Session 12. Geometry and Topology of Manifolds

Fundamental class and invariants of representations

Thilo Kuessner, Korea Institute for Advanced Study, Korea
Consider representations \(\rho\colon \pi_1M\to GL(n,{\mathbb C})\) of the fundamental group of a compact, aspherical manifold. Some topological invariants like the volume and the Chern-Simons invariant can be computed by looking at \((B\rho)_*\left[M\right]\in H_*(GL(n,{\mathbb C}))\), that is, the image of the fundamental class \(\left[M\right]\in H_*(M)\) in the homology of the general linear group. We will discuss topological properties of such invariants, in particular their invariance under mutation.
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