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Krzyż Conjecture


The Krzyż conjecture asserts that every analytic function f(z)=sum_(k=0)^(infty)a_kz^k from the unit disk to the punctured unit disk satisfies |a_n|<=2/e for every positive integer n. The proposed extremal functions are

 f(z)=zetaexp(-(1-(epsilonz)^n)/(1+(epsilonz)^n)),

where |zeta|=|epsilon|=1.

Wikström (2026) proved the conjecture, including the equality characterization, for n=6. The proof combines an analytic reduction with rigorous computer-assisted exclusion of extremals with fewer than six atoms in their integral representation. The general conjecture remains open.

Wikström (2026) reports using Claude for numerical exploration and verification-code development, with a separate GPT-6 Astra code review. The author checked the arguments and code.


See also

Analytic Function, Taylor Series, Unit Disk

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References

Wikström, F. "A Computer-Assisted Proof of Krzyż's Conjecture for the Sixth Coefficient." 10 Oct 2026. https://arxiv.org/abs/2610.15206.

Cite this as:

Weisstein, Eric W. "Krzyż Conjecture." From MathWorld--A Wolfram Resource. https://mathworld.wolfram.com/KrzyzConjecture.html

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