English

Logarithmic capacity of random $G_\delta$-sets

Dynamical Systems 2020-12-04 v1 Mathematical Physics math.MP Probability

Abstract

We study the logarithmic capacity of GδG_\delta subsets of the interval [0,1].[0,1]. Let SS be of the form \begin{align*} S=\bigcap_m \bigcup_{k\ge m} I_k, \end{align*} where each IkI_k is an interval in [0,1][0,1] with length lkl_k that decrease to 00. We provide sufficient conditions for SS to have full capacity, i.e. Cap(S)=Cap([0,1])\mathop{\mathrm{Cap}}(S)=\mathop{\mathrm{Cap}}([0,1]). We consider the case when the intervals decay exponentially and are placed in [0,1][0,1] randomly with respect to some given distribution. The random GδG_\delta sets generated by such distribution satisfy our sufficient conditions almost surely and hence, have full capacity almost surely. This study is motivated by the GδG_\delta set of exceptional energies in the parametric version of the Furstenberg theorem on random matrix products. We also study the family of GδG_\delta sets {S(α)}α>0\{S(\alpha)\}_{\alpha>0} that are generated by setting the decreasing speed of the intervals to lk=ekα.l_k=e^{-k^\alpha}. We observe a sharp transition from full capacity to zero capacity by varying α>0\alpha>0.

Cite

@article{arxiv.2012.01593,
  title  = {Logarithmic capacity of random $G_\delta$-sets},
  author = {Fernando Quintino},
  journal= {arXiv preprint arXiv:2012.01593},
  year   = {2020}
}
R2 v1 2026-06-23T20:41:22.375Z