The Constant Case

Here, we consider SGn in the case in which all resistances are constant. Then our harmonic extension matrix. We can use either electrical networks or harmonic extension matrices to determine (although we haven't proven in general) that the renormalization factor is n/(n+2) (that is, kij/cij=(n+2)/n). We have a harmonic extension rule that the value of a first generation point is a weighted average of the boundary points, with neighboring vertices given the weight 2/(n+2) and all others given the weight 1/(n+2).

The limiting case, as n goes to infinity, has all points except for the boundary points equal to the average of the boundary values in harmonic functions. If we subtract a (zero-energy) constant function to make the average zero, then the level one energy, and hence all energies, is equal to the l^2 ("little L 2") measure of the function evaluated at the boundary points. The main problem with this measure is that it is not self-similar. We can't take energy at one level and write it as a weighted sum of energies at more refined levels.

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