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17:20
@XanderHenderson what is fractal geometry anyway?
like sierpinski's gasket etc?
 
1 hour later…
18:24
@user334732 Fractal geometry is the study of the geometry of fractals. :)
And tautologies are tautological. :P
Basically, "fractals" are sets in metric spaces which have somewhat pathological properties.
There is no one agreed upon definition, but Mandelbrot suggested that sets with "interesting" dimensional properties should be considered fractal---his own first attempt at a definition was a set with Hausdorff dimension strictly exceeding topological dimension.
Some folk attempt to do analysis on fractals (Kigami and Strichartz, for example). They are interested in differential (or pseudo-differential) operators on fractals, and employ some ideas which look similar to those employed by differential geometers.
I am more interested in the actual geometry of such sets, as described by the interplay between measure and metric. My primary tools are zeta functions associated to fractal sets (or metric spaces), which can be used to recover some geometric properties.
19:23
@XanderHenderson Did you ever see this fractal?
Imagine an infinite sequence going 1011011011011011...
And a noninjective map going from that to 1
Now imagine every 1 in that first sequence has a sequence 1011011011011011... mapped to it
But none of the 0's do
Now continue... so every 1 has infinitely many sequences mapping to it
So you have a sequence $\Bbb N^0\leftarrow\Bbb N^1\leftarrow\Bbb N^2\ldots$
Does that look like anything you studied?
In this sequence the limit $\Bbb N^{<\omega}$ is countable
@XanderHenderson It seems likely fractal tools would be useful in analysing this but zeta functions (as a general idea) associated to fractal sets is greek to me.
19:48
@XanderHenderson I'm not sure if this is an expression of how measure and metric interplay here, but as this approaches its limit, it has the (I think very interesting property) of its limit being the identity map. I just wondered if you had any knowledge that might enable me to understand it better?
 
3 hours later…
22:33
@user334732 I don't understand the construction. Can provide a reference?

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