On subradically sifted sums related to Alladi's higher order duality between prime factors
Yazan Alamoudi
TL;DR
This work tackles quantitative estimates for the higher-order Alladi dualities by analyzing the sums $M_{k,\omega}(x,y)$ in a refined sifting window $y \le Y_0\exp\big(\mathscr{p}\frac{\log x}{(\log\log (x+1))^{1+\varepsilon}}\big)$ using a variant of the Selberg–Delange method. The author develops an explicit contour-integral framework with a Hankel-type path and introduces the constants $\Gamma_{m,N}$ to capture higher-order gamma-derivative contributions, yielding a main term of the form $\frac{x}{\log x}$ times a structured sum with $\Gamma_{i,j}$ and related coefficients, plus rigorous error bounds. A companion general upper-bound result extends the analysis to larger sifting ranges, giving subradical- and radical-growth-based interpretations via a new partial-order framework that clarifies the optimality of the chosen sifting rate. Together, these results advance the quantitative understanding of Alladi's higher-order dualities and provide tools for accessing higher-order terms in related analytic-arithmetic problems, with potential implications for the study of arithmetic functions under radical-like dominance.
Abstract
In this paper, I utilize a variant of the Selberg--Delange method to find quantitative estimates of the sums \[M_{k,ω}(x,y)=\sum_{\substack{p_{1}(n)> y\\ n\leq x} } μ(n) {ω(n)-1\choose k-1},\] where $y$ can grow with $x$ but we must have $y\leq Y_0\exp(\mathscr{p}\frac{\log x}{(\log\log (x+1))^{1+ε}})$ with $Y_0,\mathscr{p},ε>0$. Moreover, I give preliminary upper bounds for the general range $1.9\leq y\leq x^{\frac{1}{k}}$. In addition, I formalize the notions of subradical and radical dominance and discuss their relevance to the analytic approach of the study of arithmetic functions. Lastly, I give a fascinating formula related to the derivatives of the gamma function and the Hankel contour, which should be relevant for those employing the Selberg--Delange method to obtain higher-order terms.
