Geometry and topology · Oct 6, 2026

Failure of rational injectivity for maximal coarse assembly

Constructs a uniformly discrete bounded-geometry space whose maximal coarse assembly map is not rationally injective. The example is a coarse disjoint union of finite connected graphs of uniformly bounded degree, with an infinite-order kernel class. A companion gives the analogous failure for reduced coarse assembly, disproving the rational coarse Novikov conjecture.

Contributors

Unreleased OpenAI model

AI systems: Unreleased OpenAI model

Sources