2 papers
math.GT2026
A counterexample to the wrapping number conjecture
Qiuyu Ren
We exhibit an annular knot with wrapping number four whose Kauffman bracket has annular degree at most two. This disproves the wrapping number conjecture.
math.GR2026
Small undecidable groups and unrecognizable 4-manifolds
Marc Kegel, Shana Yunsheng Li, Qiuyu Ren
We construct a -generator -relator group with unsolvable word problem. We use the group to construct two fixed-size Adian--Rabin families of group presentations, one with …