×

On the symmetry of divisor sums functions in almost all short intervals. (English) Zbl 1087.11059

The method used in several papers by the present author to investigate the symmetry of distribution of various arithmetic functions \(f(n)\) about \(x\) in short intervals \([x- h,x+ h]\) is to study the “symmetry integral” \[ I_f(N, h):= \sum_{N< x\leq 2N}\,\Biggl| \sum_{|n-x|\leq h} \text{sgn}(n- x)f(n)\Biggr|^2,\tag{\(*\)} \] where \(h= o(N)\) as \(N\to\infty\) and \(\text{sgn}(t)={1\over|t|}\) if \(t\neq 0\). This approach has its origins in a paper [J. Math. Soc. Japan 45, No. 3, 447–458 (1993; Zbl 0787.11038)] by J. Kaczorowski and A. Perelli. The objective of the current paper is to study \((*)\) when \(f(n)\) is the divisor function \(\sigma_{-s}(n)= \sum_{d|n| d^{-s}}\), where \(s\in\mathbb{C}\), \(\text{Re}(s) =\sigma> 0\). Using an asymptotic version of the large sieve, the author establishes in Theorem 1 a formula for \(I_s(N,h)\) (given by \((*)\) with \(f= \sigma_{-s}\)) with a remainder term that is \(o(N)\) as \(N\to\infty\) under the assumption that \(h= N^\theta\) with \(0<\theta<\min({1\over 2},{\sigma\over 2+\sigma})\), \(\sigma> 0\). When also \(\theta< {1\over 2(2+\sigma)}\), it is shown in Corollary 1 that \[ I_s(N,h)= 2{|\zeta(1+ s)|^2\over \zeta(2+ 2\sigma)} N\eta^{(h)}(2\sigma)+ o(N), \] where \(n^{(h)}(2\sigma)\) is given by an infinite series depending on \(h\) that converges in \(\sigma> 0\).

MSC:

11N37 Asymptotic results on arithmetic functions
11N36 Applications of sieve methods

Citations:

Zbl 0787.11038