Lu–Wang weak polymatroidality conjecture

Let Δ\Delta be a pure vertex-decomposable simplicial complex on the vertex set [n][n], and let IΔ∨I_{\Delta^{\vee}} denote the Stanley–Reisner ideal of its Alexander dual. The Lu–Wang conjecture asks whether IΔ∨I_{\Delta^{\vee}} is weakly polymatroidal for every such Δ\Delta.

References

Primary source

arXiv

Additional references

Progress summary

Refreshed
Claimed progress

A 2026 preprint reports that the conjecture fails for infinitely many chessboard examples, but the broader question remains open.

The Lu–Wang conjecture predicts weak polymatroidality for the relevant Alexander-dual Stanley–Reisner ideals of pure vertex-decomposable complexes. The reported counterexamples concern only an infinite family of chessboard-complex ideals, so they do not settle the full statement.

Known related counterexample

A separate example shows that a vertex-splittable Alexander-dual ideal need not be weakly polymatroidal, for ideals generated in degrees greater than 22; the source does not identify it as a resolution of the Lu–Wang conjecture.

September 2026 chessboard-complex counterexamples

A September 2026 report citing Ghosh and Selvaraja’s preprint says weak polymatroidality fails for an infinite family of chessboard-complex ideals. This is substantive claimed progress, but the broader conjecture for all pure vertex-decomposable complexes remains unresolved.

Current status (as of September 2026): Weak polymatroidality is claimed to fail for an infinite chessboard-complex family, while the general pure vertex-decomposable case remains open.

Sources

Solutions 0

No solutions have been posted yet.