Heim–Neuhauser's log-concavity challenge for D'Arcais polynomials

Less than 1 year old · traced to

Let Pnσ(X)=∑k=0npnσ(k)XkP_n^\sigma(X)=\sum_{k=0}^n p_n^\sigma(k)X^k be the D'Arcais polynomial defined by

∏m=1∞(1−qm)−X=∑n=0∞Pnσ(X)qn,\prod_{m=1}^\infty(1-q^m)^{-X}=\sum_{n=0}^\infty P_n^\sigma(X)q^n,

and call a sequence (ak)k∈N(a_k)_{k\in\mathbb{N}} log-concave at k≥1k\geq 1 when ak2≥ak−1ak+1a_k^2\geq a_{k-1}a_{k+1}. Heim–Neuhauser's challenge. For every n∈Nn\in\mathbb{N}, the sequence (pnσ(k))k∈N(p_n^\sigma(k))_{k\in\mathbb{N}} is log-concave at each k≥1k\geq 1. This is a proposed coefficient-growth property for the D'Arcais polynomials; the source supplies no resolution status.

References

Primary source

Johann Stumpenhusen, “On the Log-Concavity of the D'Arcais Polynomials for Normalised Functions”, arXiv:2607.14961 (2026).

Progress summary

Never refreshed

Nothing recorded yet. Refresh searches the literature and the public web for attempts on this problem, and writes the first summary here.

Solutions 0

No solutions have been posted yet.