2 papers
math.GT2025
Rotation index, Milnor--Munkres--Novikov pairing, and group actions on manifolds
Mauricio Bustamante, Bena Tshishiku
We introduce an invariant of a pair of commuting invertible matrices that we call the rotation index. We apply this invariant, together with the Milnor--Munkres--Novikov pairing, t…
math.GT2025
The Euler class of infinite-type surface bundles
Mauricio Bustamante, Rita Jiménez Rolland, Israel Morales
We study the Euler class of smooth orientable infinite-type surface bundles with a section. For many such surfaces, we show that this cohomology class is nontrivial, and that the b…