The Liouville function has super-linear block growth

You need to know: Prime factorisation of positive integers, limits.

Background: For a positive integer n, let \Omega(n) be the number of prime factors of n, counted with multiplicity. Function \lambda(n)=(-1)^{\Omega (n)} is known as the Liouville function. The block complexity P_{\lambda}(n) of \lambda(n) is the number of sign patterns of size n that are taken by consecutive values of \lambda(n).

The Theorem: On 2nd August 2017, Nikos Frantzikinakis and Bernard Host submitted to arxiv a paper in which they proved, among other results, that \lim\limits_{n\to\infty}\frac{P_{\lambda}(n)}{n}=\infty.

Short context: The Chowla conjecture predicts, as one may naturally expect, that all possible sign patterns of size n are taken by the Liouville function. In other words, P_{\lambda}(n) is conjectured to be 2^n. However, the best lower bound for P_{\lambda}(n) before 2017 was only P_{\lambda}(n)\geq n+5 for n\geq 3. The Theorem significantly improves this bound.

Links: Free arxiv version of the original paper is here, journal version is here.

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