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Hausdorff capacity and Lebesgue measure. (English) Zbl 0879.28005

Summary: It is shown that for any \(r \in (0,1)\) and for any continuous function from the unit interval to itself, there are sets of arbitrarily small Lebesgue measure whose preimage has arbitrarily large \(r\)-Hausdorff capacity. This is generalized to functions from the unit square to the interval.

MSC:

28A12 Contents, measures, outer measures, capacities
26A03 Foundations: limits and generalizations, elementary topology of the line
26A15 Continuity and related questions (modulus of continuity, semicontinuity, discontinuities, etc.) for real functions in one variable
28A35 Measures and integrals in product spaces
28A78 Hausdorff and packing measures