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Results tagged with ergodic-theory
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user 37555
Dynamical systems on measure spaces, invariant measures, ergodic averages, mixing properties.
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About positive upper density
Suppose that $(S-n)\cap S$ has upper density 0 for all $n\leq N$. Then the density of the set of integers $x$, such that $|[xN, (x+1)N]\cap S|\geq 2$ is also 0, hence the upper density of $S$ is $\leq …
