What Does o(1) Mean in the Longest Increasing Subsequence Problem?

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SUMMARY

The discussion centers on the Longest Increasing Subsequence (LIS) problem, specifically addressing the expected length E[X] of the LIS for i.i.d. random variables uniformly distributed on [0,1]. The key conclusion is that E[X] is bounded below by (1-o(1))(1-e^{-1})√n, which is a stronger result than the previously established bound of E[X] ≥ 1/2√n derived from Erdős' lemma. The notation "o(1)" indicates a term that approaches zero as n increases, providing a more precise asymptotic behavior of the expected length.

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Naumberg
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Problem:

"Let [itex]x_1, ..., x_n[/itex] be i.i.d random variables uniformly on [0,1]. Let [itex]X[/itex] be the length of the longest increasing subsequence of [itex]x_1, ..., x_n[/itex]. Show that [itex]E[X] \ge (1-o(1))(1-e^{-1}) \sqrt{n}[/itex]."


Hi forum!

Using the Erdos' lemma I can only deduce that [itex]E[X] \ge \frac{1}{2} \sqrt{n}[/itex], which is a weaker bound unfortunately.

I would appreciate any further ideas!

Thanks for your help,
Michael
 
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What does the notation "[itex]o(1)[/itex]" mean in this context?
 

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