Product gales and Finite state dimension
Abstract
In this work, we introduce the notion of product gales, which is the modification of an -gale such that 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 -bet finite-state gambler is one that can place separate bets at each symbol. We call the notion of finite-state dimension, characterized by product gales induced by -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 -bet finite state -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}
}