English

Unimodular Fake Mobius Functions

Number Theory 2026-01-01 v2

Abstract

We study \emph{unimodular fake} μs\mu's, i.e. multiplicative functions f:NS1{0}\mathfrak f: \N \to \mathbb{S}^1 \cup \{0\} determined by a fixed sequence {εk}k0S1{0}\{\varepsilon_k\}_{k\ge 0} \subset \mathbb{S}^1 \, \cup \, \{0\} via the rule f(pk)=εk\mathfrak f(p^k)=\varepsilon_k for every prime pp and k0k \ge 0. The Dirichlet series of a given f\mathfrak f admits the Euler product Ff(s)=n1f(n)ns=pgf(ps),gf(u)=k0εkuk, F_{\mathfrak f}(s)=\sum_{n\ge1}\frac{\mathfrak f(n)}{n^s} =\prod_p g_{\mathfrak f}(p^{-s}),\qquad g_{\mathfrak f}(u)=\sum_{k\ge0}\varepsilon_k u^k, and the canonical zeta-factorization Ff(s)=ζ(s)zζ(2s)wGf(s),z=ε1,  w=ε2ε1(ε1+1)2, F_{\mathfrak f}(s)=\zeta(s)^{\,z}\,\zeta(2s)^{\,w}\,G_{\mathfrak f}(s), \qquad z=\varepsilon_1,\ \ w=\varepsilon_2-\frac{\varepsilon_1(\varepsilon_1+1)}{2}, where Gf(s)G_{\mathfrak f}(s) is a holomorphic Euler product on s>1/3\Re s>1/3. Assuming the Riemann hypothesis and Simple Zeros Conjecture, we derive an explicit formula for Afexp(x)=n1f(n)en/xA_{\mathfrak f}^{\exp}(x)= \sum_{n \ge 1} \mathfrak f(n) \, e^{-n/x} of the form Afexp(x)Δ1(x;z,w)=Δ1/2(x;z,w)  +  ρΔρ(x;z,w,f)  +  E(x). A_{\mathfrak f}^{\exp}(x) -\Delta_1(x;z,w) = \Delta_{1/2}(x;z,w)\;+\;\sum_{\rho}\Delta_\rho(x;z,w,\mathfrak f)\;+\;\mathcal E(x). To our knowledge, our expansion is the first extension of the Selberg-Delange method for Dirichlet series of the form ζ(s)zζ(2s)wG(s)\zeta(s)^{\,z}\,\zeta(2s)^{\,w}\,G(s) that, beyond the main term from s=1s=1, also extracts lower-order contributions from the singularities on the critical line (s)=1/2\Re(s)=1/2. On the other hand, we introduce a notion of \emph{bias} at the natural scale x1/2(\Logx)w1x^{1/2}(\Log x)^{w-1} and obtain an explicit criterion distinguishing \emph{persistent}, \emph{apparent}, and \emph{unbiased} behavior in this regime.

Keywords

Cite

@article{arxiv.2512.18936,
  title  = {Unimodular Fake Mobius Functions},
  author = {Ali Saraeb},
  journal= {arXiv preprint arXiv:2512.18936},
  year   = {2026}
}
R2 v1 2026-07-01T08:35:57.256Z