Gerhard Roehrle

collaborators

3 papers

math.CO2025

MAT-Freeness is not combinatorial

Torsten Hoge, Gerhard Roehrle

We show that the notion of MAT-freeness for hyperplane arrangements depends on the underlying field. In particular, MAT-freeness is not combinatorial.

math.CO2025

On Universal derivations for multiarrangements

Takuro Abe, Shota Maehara, Gerhard Roehrle +1

The study of universal derivations for arbitrary multiarrangements and multiplicity functions was initiated by Abe, Röhrle, Stump, and Yoshinaga in 2024 which focused on arrangemen…

math.RT2025

Invariants in the cohomology of the complement of quaternionic reflection arrangements

Lorenzo Giordani, Gerhard Roehrle, Johannes Schmitt

Let $A$ be a hyperplane arrangement in a vector space $V$ and $G \leq G L (V)$ a group fixing $A$ . In case when $G$ is a complex reflection group and $\mathcal A=\m…