“…On the other hand, if the holes in the carpet are not too small, then [36, Theorem 4.2] applies (see Remark 4.9 below) and tells that within the 2 -space of 1-forms F I G U R E 1 On the left, the standard self-similar Sierpinski carpet. On the right, a non-self-similar Sierpinski carpet (1∕3,1∕5,1∕7,… ) from the paper of Mackay, Tyson and Wildrick, [48] (see p. 3 of arXiv:1201.3548 for the precise definition) the locally harmonic 1-forms are dense in the orthogonal complement of the exact 1-forms. Here we call a square integrable 1-form locally harmonic if we can find a finite open cover { } ∈ of and functions ℎ , ∈ , harmonic in the Dirichlet form sense, such that for any ∈ we have = ℎ , where denotes the exterior derivation.…”