Massey vanishing conjecture for Galois cohomology

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Let kk be a field, let pp be a prime, and let n≥3n\geq 3. For cohomology classes

α0,…,αn−1∈H1(k,Fp),\alpha_0,\dots,\alpha_{n-1}\in H^1(k,{\mathbf F}_p),

consider the nn-fold Massey product ⟨α0,…,αn−1⟩⊆H2(k,Fp)\langle\alpha_0,\dots,\alpha_{n-1}\rangle\subseteq H^2(k,{\mathbf F}_p). Massey vanishing conjecture. If this Massey product is non-empty, then it contains 0∈H2(k,Fp)0\in H^2(k,{\mathbf F}_p). The conjecture extends the vanishing of triple Massey products from coefficients in F2{\mathbf F}_2 to all primes and all lengths, and connects arithmetic Galois cohomology with the topology of link complements. It remains open in general.

References

Primary source

Yonatan Harpaz and Olivier Wittenberg, “The Massey vanishing conjecture for number fields”, arXiv:1904.06512 (2022).

Progress summary

Refreshed
Open

The conjecture is proved in important special settings, but no result found settles it for every field and every length.

Mináč and Tân formulated the conjecture that every defined higher Massey product contains zero. The full assertion remains open beyond its established special cases.

Known results

  • All lengths n≥3n \ge 3 over number fields, for every prime pp (2019 paper).
  • Triple products for p=2p=2 (Hopkins–Wickelgren).
  • Triple products for fields containing a primitive ppth root of unity (Matzri; Efrat–Matzri; Mináč–Tân, 2014).
  • Triple products for odd primes via generalized Bockstein maps (2020).

August 25, 2023 conditional result

Merkurjev and Scavia proved vanishing for triple products, and for some degenerate fourfold products, under a formal Hilbert 9090 hypothesis on a profinite group with character θ:G→Zp×\theta:G\to\mathbb{Z}_p^\times. This does not settle arbitrary fields and arbitrary nn.

Current status (as of September 2026): The conjecture is settled for number fields and several special cases, but the full assertion for arbitrary fields and general n≥3n \ge 3 remains open.

Sources

Solutions 0

No solutions have been posted yet.