Asymmetric companion-zero conjecture for the smooth divisor-sum indicator

From papers

For x>0x>0 and steepness parameter κ>0\kappa>0, define the smooth divisor-sum indicator by

Pσ(x;κ)=(i=2ϕκ ⁣(ix+1)F(x,i)i)x.\mathcal P_{\sigma}(x;\kappa)=\left(\sum_{i=2}^{\infty}\phi_{\kappa}\!\left(\frac{i}{x+1}\right)\frac{F(x,i)}{i}\right)-x.

For each odd prime p3p\ge 3, the asymmetric companion-zero conjecture. For sufficiently large κ\kappa, Pσ(;κ)\mathcal P_{\sigma}(\cdot;\kappa) has an asymmetric pair of real zeros flanking pp: a left zero xp(κ)x_p^-(\kappa) satisfying

pxp(κ)pe2κ/(p+1)(κ),p-x_p^-(\kappa)\asymp p\,\mathrm e^{-2\kappa/(p+1)}\qquad(\kappa\to\infty),

and a right zero whose distance from pp remains bounded away from zero as κ\kappa\to\infty. Numerics also indicate

Pσ(p;κ)pe2κ/(p+1).\mathcal P_{\sigma}(p;\kappa)\approx-p\,\mathrm e^{-2\kappa/(p+1)}.

The claimed asymmetry contrasts with the two zeros approaching pp for Pτ\mathcal P_\tau; the limiting integer values of Pσ\mathcal P_\sigma vanish precisely at primes, while the asserted right companion does not approach pp.

Progress summary

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

Sources & referencesView supporting material

Primary source

Sebastian Fuchs, “Fejér-Kernel Prime Indicators”, arXiv:2506.18933 (2025).

Solutions 0

No solutions have been posted yet.