152 research outputs found

    A note on the Liouville function in short intervals

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    In this note we give a short and self-contained proof that, for any δ>0\delta > 0, xnx+xδλ(n)=o(xδ)\sum_{x \leq n \leq x+x^\delta} \lambda(n) = o(x^\delta) for almost all x[X,2X]x \in [X, 2X]. We also sketch a proof of a generalization of such a result to general real-valued multiplicative functions. Both results are special cases of results in our more involved and lengthy recent pre-print.Comment: 12 pages, expository not

    Large deviations in Selberg's central limit theorem

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    Following Selberg it is known that as T → ∞, [formula] uniformly for Δ ≤ (log log log T)^((1/2) - ε). We extend the range of Δ to Δ « (log log T)^((1/10) - ε). We also speculate on the size of the largest Δ for which the above normal approximation can hold and on the correct approximation beyond this point

    Correlations of the von Mangoldt and higher divisor functions II. Divisor correlations in short ranges

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    We study the problem of obtaining asymptotic formulas for the sums X<n2Xdk(n)dl(n+h)\sum_{X < n \leq 2X} d_k(n) d_l(n+h) and X<n2XΛ(n)dk(n+h)\sum_{X < n \leq 2X} \Lambda(n) d_k(n+h), where Λ\Lambda is the von Mangoldt function, dkd_k is the kthk^{\operatorname{th}} divisor function, XX is large and kl2k \geq l \geq 2 are real numbers. We show that for almost all h[H,H]h \in [-H, H] with H=(logX)10000klogkH = (\log X)^{10000 k \log k}, the expected asymptotic estimate holds. In our previous paper we were able to deal also with the case of Λ(n)Λ(n+h)\Lambda(n) \Lambda(n + h) and we obtained better estimates for the error terms at the price of having to take H=X8/33+εH = X^{8/33 + \varepsilon}.Comment: 46 pages; incorporated referee comments and corrected a few additional typo
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