3 papers
math.AT2026
Bond thickenings of the simplicial boundary of Outer space
Benjamin Brück
We study the simplicial boundary of Culler-Vogtmann Outer space via thickenings defined by graph-theoretic connectivity. Let be the subcomplex of the fr…
math.NT2025
Top-degree rational cohomology in the symplectic group of a number ring
Benjamin Brück, Zachary Himes
Let be a number field with ring of integers . We show that if is not a principal ideal domain, then the symplectic group has…
math.QA2024
Weight 2 cohomology of graph complexes of cyclic operads and the handlebody group
Michael Borinsky, Benjamin Brück, Thomas Willwacher
We compute the weight 2 cohomology of the Feynman transforms of the cyclic (co)operads and , and the top weight cohomology of the Feynman transfor…