arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2012.15507math.NTmath.PR
收藏

具有随机乘性系数的多项式的矩

Moments of polynomials with random multiplicative coefficients

Jacques Benatar, Alon Nishry, Brad Rodgers

AI总结:

本文研究了Rademacher或Steinhaus随机乘性函数多项式在单位圆上的矩,证明其在特定范围内均方收敛于高斯矩,并据此证明了几乎必然的Salem-Zygmund型中心极限定理及多项式最大值的渐近界。

摘要:

对于Rademacher或Steinhaus随机乘性函数$X(n)$,我们考虑随机多项式$$P_N(θ) = \frac1{\sqrt{N}} \sum_{n\leq N} X(n) e(nθ),$$并证明其在单位圆上的$2k$-阶矩$$\int_0^1 \big| P_N(θ) \big|^{2k}\\, dθ$$在均方收敛意义下趋向于高斯矩,且对$k \ll (\log N / \log \log N)^{1/3}$一致成立,但与独立同分布系数情形相反,此行为在$k$更大时不再保持。我们利用这些估计来(i)给出$P_N(θ)$的一个几乎必然的Salem-Zygmund型中心极限定理的证明,该结果此前由Harper在其未发表的工作中通过不同方法获得;(ii)证明渐近几乎必然有$$(\log N)^{1/6 - \varepsilon} \ll \max_θ|P_N(θ)| \ll \exp((\log N)^{1/2+\varepsilon}),$$对所有$\varepsilon > 0$成立。

英文摘要:

For $X(n)$ a Rademacher or Steinhaus random multiplicative function, we consider the random polynomials $$ P_N(θ) = \frac1{\sqrt{N}} \sum_{n\leq N} X(n) e(nθ), $$ and show that the $2k$-th moments on the unit circle $$ \int_0^1 \big| P_N(θ) \big|^{2k}\, dθ$$ tend to Gaussian moments in the sense of mean-square convergence, uniformly for $k \ll (\log N / \log \log N)^{1/3}$, but that in contrast to the case of i.i.d. coefficients, this behavior does not persist for $k$ much larger. We use these estimates to (i) give a proof of an almost sure Salem-Zygmund type central limit theorem for $P_N(θ)$, previously obtained in unpublished work of Harper by different methods, and (ii) show that asymptotically almost surely $$ (\log N)^{1/6 - \varepsilon} \ll \max_θ|P_N(θ)| \ll \exp((\log N)^{1/2+\varepsilon}), $$ for all $\varepsilon > 0$.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑