Normal numbers and limit computable Cantor series
arXiv:1404.2178 · doi:10.1215/00294527-2017-0004
Abstract
Given any oracle, A, we construct a basic sequence Q, computable in the jump of A, such that no A-computable real is Q-distribution-normal. A corollary to this is that there is a Delta^0_{n+1} basic sequence with respect to which no Delta^0_n real is distribution-normal. As a special case, there is a limit computable sequence relative to which no computable real is distribution-normal.
5 pages