English

Product gales and Finite state dimension

Information Theory 2025-02-11 v1 math.IT

Abstract

In this work, we introduce the notion of product gales, which is the modification of an ss-gale such that kk separate bets can be placed at each symbol. The product of the bets placed are taken into the capital function of the product-gale. We show that Hausdorff dimension can be characterised using product gales. A kk-bet finite-state gambler is one that can place kk separate bets at each symbol. We call the notion of finite-state dimension, characterized by product gales induced by kk-bet finite-state gamblers, as multi-bet finite-state dimension. Bourke, Hitchcock and Vinodchandran gave an equivalent characterisation of finite state dimension by disjoint block entropy rates. We show that multi-bet finite state dimension can be characterised using sliding block entropy rates. Further, we show that multi-bet finite state dimension can also be charatcterised by disjoint block entropy rates. Hence we show that finite state dimension and multi-bet finite state dimension are the same notions, thereby giving a new characterisation of finite state dimension using kk-bet finite state ss-gales. We also provide a proof of equivalence between sliding and disjoint block entropy rates, providing an alternate, automata based proof of the result by Kozachinskiy, and Shen.

Keywords

Cite

@article{arxiv.2502.06208,
  title  = {Product gales and Finite state dimension},
  author = {Akhil S},
  journal= {arXiv preprint arXiv:2502.06208},
  year   = {2025}
}