I use to denote the Hausdorff dimension of a set and to denote its Lebesgue measure. It is easy to see from the definition of Hausdorff dimension that if , then . The converse is not true, and there are many cases where yet . So the question:
What was the first (or most elementary) example of this phenomenon?
After some looking around, I was able to prove that a central Cantor set with ratio of dissection satisfies the condition I want. It is easy to see that since at step of the process to construct this Cantor set, it has measure which in this case limits to 0, but for the Hausdorff dimension I required a non-trivial result from the paper Sums of Cantor sets (Cabrelli, Hare, Molter) that gave the formula
.
This result is fairly recent and sophisticated, and I feel that there should be older and simpler examples.
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