We prove various obstructions to the existence of regular maps (or coarse embeddings) between commonly studied spaces. For instance, there is no regular map (or coarse embedding) for , or whenever is a bounded degree graph with subexponential growth, where is the -regular tree. We also resolve a question of Benjamini-Schramm-Timár, proving that there is no regular map whenever is a bounded degree graph with at most polynomial growth, and no quasi-isometric embedding whenever has subexponential growth. Finally, we show that there is no regular map where is the free group on two generators. To prove these results, we introduce and study generalizations of asymptotic dimension which allow unbounded covers with controlled growth. For bounded degree graphs, these invariants are monotone with respect to regular maps (hence coarse embeddings).

生成讲解博客的中文版本

生成AI智能校验的中文版本