English

Pointwise regularity and irregularity of energy densities on $N$-dimensional Sierpinski gaskets

Analysis of PDEs 2026-05-26 v2 Probability

Abstract

We study the pointwise regularity of energy densities associated with harmonic functions on the NN-dimensional Sierpinski gasket (N2)(N\ge 2) with respect to the Kusuoka measure. For any nonconstant harmonic function, we prove that every Borel representative of the density is discontinuous at every point of a set of full Kusuoka measure. In sharp contrast, on each one-dimensional edge of the gasket -- itself a set of zero Kusuoka measure -- the density admits a canonical pointwise version, which is γN\gamma_N-H\"older continuous on that edge with the explicit and optimal exponent γN=log2{(4N+5+1)/(4N+51)}\gamma_N=\log_2 \{(\sqrt{4N+5}+1)/(\sqrt{4N+5}-1)\}.

Keywords

Cite

@article{arxiv.2602.06642,
  title  = {Pointwise regularity and irregularity of energy densities on $N$-dimensional Sierpinski gaskets},
  author = {Masanori Hino and Kanji Inui and Kohei Nitta},
  journal= {arXiv preprint arXiv:2602.06642},
  year   = {2026}
}

Comments

31 pages, 2 figures. Major revision; title, abstract, introduction, and the proof of the optimal H\"older exponent substantially revised