# Polytope invariant of a manifold

## [edit] 1 Problem

The motivation for this question is given by [Friedl&Lück&Tillmann2016]. The authors associate to any -acyclic closed oriented manifold a certain invariant which can be understood as a formal difference of polytopes in ,

*Question*: Is there a geometric definition of that invariant?

*Question*: What about realization results? In dimension this is an old unsolved question of which Thurston polytopes are realized by aspherical 3-manifolds.

In dimensions and higher, using surgery theory, we know exactly which polytopes can be realized, but in dimensions to , it is not known. In dimension this may be difficult and depend on whether we study smooth or topological manifolds.

The paper by Friedl, Lück and Tillmann mentioned above proposes several open questions on this topic.

This question was posed by Stefan Friedl at the MATRIX meeting on Interactions between high and low dimensional topology.

## [edit] 2 References

- [Friedl&Lück&Tillmann2016] S. Friedl and W. Lück and S. Tillmann,
*Groups and polytopes*. Available at the arXiv:1611.01857v1.