Abstract:
We study constructive and resource-bounded scaled dimension as an
information content measure and obtain several results that parallel
previous work on unscaled dimension. Scaled dimension for
finite strings is developed and shown to be closely related to
Kolmogorov complexity. The scaled dimension of an infinite sequence
is characterized by the scaled dimensions of its prefixes. We
obtain an exact Kolmogorov complexity characterization of scaled
dimension.
Juedes and Lutz (1996) established a small span theorem for P/poly-Turing reductions which asserts that for any problem A in ESPACE, either the class of problems reducible to A (the lower span) or the class of problems to which A is reducible (the upper span) has measure 0 in ESPACE. We apply our Kolmogorov complexity characterization to improve this to (-3)rd-order scaled dimension 0 in ESPACE. As a consequence we obtain a new upper bound on the Kolmogorov complexity of Turing-hard sets for ESPACE.