Cancellation conjecture for nonorientable 4-manifolds with cyclic fundamental group

Let M2pM_{2p} be a closed topological nonorientable 44-manifold with cyclic fundamental group of order 2p2p, where p>1p>1 is odd. Theorem Cancellation Homeomorphism Classes asserts that M2p#2(S2×S2)M_{2p}\mathbin{\#}2\cdot(S^2\times S^2) is homeomorphic to exactly one 44-manifold in the specified collection, with the corresponding classification described by the theorem. Cancellation conjecture. The same conclusion should hold for M2pM_{2p} without any additional copies of S2×S2S^2\times S^2. This would resolve the remaining cancellation problem needed for a complete classification of these manifolds; the source describes it as a difficult algebraic problem and does not state that it has been solved.

Sources & referencesView supporting material

Primary source

Rafael Torres, “Topological classification of certain nonorientable 4-manifolds with cyclic fundamental group of order 2 mod 4”, arXiv:2601.05132 (2026).

Progress summary

Never refreshed

Nothing recorded yet. Refresh searches the literature and the public web for attempts on this problem, and writes the first summary here.

Solutions 0

No solutions have been posted yet.