Pólya’s conjecture and related sign criteria

Let λ(n)=(−1)Ω(n)\lambda(n)=(-1)^{\Omega(n)} be the Liouville function and define, for sufficiently large xx, f(x):=−∑n≤xλ(n)log⁡nnlog⁡xnf(x):=-\sum_{n\le x}\frac{\lambda(n)\log n}{\sqrt n}\log\frac{x}{n}. Is f(x)≥0f(x)\ge 0 for all sufficiently large xx?

References

Primary source

arXiv

Additional references

Progress summary

Refreshed
Claimed progress

A recent preprint gives a conditional positive answer and shows that an unconditional positive answer would imply the Riemann hypothesis, but the question remains open.

The problem asks whether the weighted Liouville sum f(x)f(x) is eventually nonnegative. This is a related sign criterion, not the original Pólya conjecture about the unweighted summatory Liouville function, which is already disproved.

Known results

  • Haselgrove (1958) disproved the original Pólya conjecture; Lehman (1960) and Tanaka (1980) produced explicit counterexamples, with Tanaka’s smallest known one at 906150257906150257.
  • For related sums Lα(x)L_\alpha(x), logarithmic-distribution results are known conditionally on the Riemann hypothesis, linear independence, and a moment bound.
  • These results do not settle eventual nonnegativity of f(x)f(x).

Recent preprint: conditional sign criterion

The preprint On variants of Pólya’s conjecture proves that eventual nonnegativity of f(x)f(x) would imply the Riemann hypothesis. Conversely, assuming the Riemann hypothesis, the Simple Zero Conjecture, and an additional convergence hypothesis, it derives f(x)∼(log⁡x)3/(12∣ζ(1/2)∣)f(x)\sim (\log x)^3/(12\lvert\zeta(1/2)\rvert) and hence eventual positivity. This is a conditional advance, not an unconditional solution, and remains unverified.

Current status (as of September 2026): The original Pólya conjecture is disproved, while the stated eventual-sign question remains open; only a conditional result is reported.

Sources

Solutions 0

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