Dual View Random Solved Random Open
PROVED This has been solved in the affirmative.
Let $z_1,z_2,\ldots \in [0,1]$ be an infinite sequence, and define the discrepancy\[D_N(I) = \#\{ n\leq N : z_n\in I\} - N\lvert I\rvert.\]Must there exist some interval $I\subseteq [0,1]$ such that\[\limsup_{N\to \infty}\lvert D_N(I)\rvert =\infty?\]
The answer is yes, as proved by Schmidt [Sc68], who later showed [Sc72] that in fact this is true for all but countably many intervals of the shape $[0,x]$.

Essentially the best possible result was proved by Tijdeman and Wagner [TiWa80], who proved that, for almost all intervals of the shape $[0,x)$, we have\[\limsup_{N\to \infty}\frac{\lvert D_N([0,x))\rvert}{\log N}\gg 1.\]

View the LaTeX source

External data from the database - you can help update this
Formalised statement? No (Create a formalisation here)
Likes this problem None
Interested in collaborating None
Currently working on this problem None
This problem looks difficult None
This problem looks tractable None
The results on this problem could be formalisable None
I am working on formalising the results on this problem None

Additional thanks to: Cedric Pilatte and Stefan Steinerberger

When referring to this problem, please use the original sources of Erdős. If you wish to acknowledge this website, the recommended citation format is:

T. F. Bloom, Erdős Problem #255, https://www.erdosproblems.com/255, accessed 2026-02-13