Holger Kammeyer

Holger Kammeyer is Junior Professor for Algebra and Geometry at Heinrich Heine University Düsseldorf's Mathematical Institute, within the Faculty of Mathematics and Natural Sciences. His research focuses on algebraic topology, profinite and arithmetic groups, and ℓ²-invariants.

Kammeyer's research explores profinite group properties, arithmetic group invariants, ℓ²-Betti numbers, Galois cohomology applications, and geometric methods in group theory. He develops techniques for studying profinite rigidity of lattices in Lie groups and invariants of S-arithmetic groups.

Recent work includes investigations of higher rank volume profiniteness, Euler characteristics of S-arithmetic groups, bounded cohomology as a profinite invariant, and Gassmann triples with special cycle types. His publications demonstrate expertise in both theoretical developments and educational materials, including textbooks on algebraic topology and ℓ²-invariants.

As Principal Investigator in multiple research initiatives, Kammeyer leads projects on geometric structures in group theory and supervises doctoral students in algebra and number theory. He organizes research events including summer schools on analytic and arithmetic groups and conferences on the interface of group theory with geometry and topology.