中文

Rademacher随机乘性函数加权和的几乎必然界

数论 2026-02-04 v4 概率论

摘要

我们证明了当 ff 为Rademacher随机乘性函数时,对任意 ϵ>0\epsilon>0,都有 nxf(n)n(loglog(x))3/4+ϵ\sum_{n \leqslant x}\frac{f(n)}{\sqrt{n}} \ll (\log\log(x))^{3/4+\epsilon} 几乎所有 ff 都成立。我们还显示存在任意大的 xx 值使得 nxf(n)n(loglog(x))1/2\sum_{n \leqslant x}\frac{f(n)}{\sqrt{n}} \gg (\log\log(x))^{-1/2}。这与Steinhaus情况不同,此时Rademacher Euler乘积的大小使得乘性混沌贡献为主导。我们也发现了在限制于具有素因子大于 x\sqrt{x} 的整数时的更精确上界,证明 nx P(n)>xf(n)n(loglog(x))1/4+ϵ\sum_{\substack{n \leqslant x \ P(n) > \sqrt{x}}}\frac{f(n)}{\sqrt{n}} \ll (\log\log(x))^{1/4+\epsilon}

关键词

引用

@article{arxiv.2501.11076,
  title  = {Almost sure bounds for weighted sums of Rademacher random multiplicative functions},
  author = {Christopher Atherfold},
  journal= {arXiv preprint arXiv:2501.11076},
  year   = {2026}
}

备注

50 pages. Comments welcome. Rewritten section 6.3 to attain a sharper bound, added references and improved introduction