Thomas–Yong–Mihalcea Grothendieck positivity inequality

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Let P\mathcal P denote the set of partitions, let G~λ\widetilde{G}_{\lambda} be the modified stable Grothendieck symmetric function, and let ⩽g⁡\leqslant_{\operatorname{g}} denote Grothendieck positivity. Thomas–Yong–Mihalcea's Grothendieck positivity conjecture. For all partitions λ,μ∈P\lambda,\mu\in\mathcal P, one has

G~λ,G~μ⩽g⁡G~λ∨μ,G~λ∧μ.\widetilde{G}_{\lambda}\\,\widetilde{G}_{\mu}\leqslant_{\operatorname{g}}\widetilde{G}_{\lambda\vee\mu}\\,\widetilde{G}_{\lambda\wedge\mu}.

The corresponding Schur-positivity inequality is proved in the paper, whereas the stronger Grothendieck-positivity assertion remains open.

References

Primary source

Swee Hong Chan, Hong Chen, Igor Pak and Daniel Soskin, “Correlation inequalities for Schur positivity”, arXiv:2606.06688 (2026).

Progress summary

Refreshed
Open

The stronger version of a known positivity inequality remains open; recent papers prove only a weaker version and report no proof or counterexample.

Thomas–Yong formulated the Grothendieck-positivity conjecture, also associated in the literature with Mihalcea's 2024 work. It asserts that the product indexed by two partitions is bounded, in Grothendieck positivity, by the products indexed by their join and meet.

Known results

  • Theorem 1.8 proves the corresponding Schur-positivity inequality G~λG~μ⩽sG~λ∨μG~λ∧μ\widetilde{G}_{\lambda}\widetilde{G}_{\mu}\leqslant_{\mathrm{s}}\widetilde{G}_{\lambda\vee\mu}\widetilde{G}_{\lambda\wedge\mu} for all partitions λ,μ\lambda,\mu.
  • The same source explicitly treats the stronger Grothendieck-positivity assertion as open and presents the Schur result only as evidence for it.

Current status (as of September 2026): The Schur-positivity inequality is proved, but the Grothendieck-positivity conjecture remains open, with no publicly reported proof, counterexample, or claimed resolution.

Sources

Solutions 0

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