,
Wolfgang Merkle,
Frank Stephan
Creative Commons Attribution 4.0 International license
Speedable numbers are real numbers which are algorithmically approximable from below and whose approximations can be accelerated nonuniformly. We begin this article by answering a question of Barmpalias by separating a strict subclass that we will refer to as superspeedable from the speedable numbers; for elements of this subclass, acceleration is possible uniformly and to an even higher degree. This new type of benign left-approximation of numbers then integrates itself into a hierarchy of other such notions studied in a growing body of recent work. We add a new perspective to this study by juxtaposing this hierachy with the well-studied hierachy of algorithmic randomness notions.
@InProceedings{holzl_et_al:LIPIcs.MFCS.2024.62,
author = {H\"{o}lzl, Rupert and Janicki, Philip and Merkle, Wolfgang and Stephan, Frank},
title = {{Randomness Versus Superspeedability}},
booktitle = {49th International Symposium on Mathematical Foundations of Computer Science (MFCS 2024)},
pages = {62:1--62:14},
series = {Leibniz International Proceedings in Informatics (LIPIcs)},
ISBN = {978-3-95977-335-5},
ISSN = {1868-8969},
year = {2024},
volume = {306},
editor = {Kr\'{a}lovi\v{c}, Rastislav and Ku\v{c}era, Anton{\'\i}n},
publisher = {Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
address = {Dagstuhl, Germany},
URL = {https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.MFCS.2024.62},
URN = {urn:nbn:de:0030-drops-206187},
doi = {10.4230/LIPIcs.MFCS.2024.62},
annote = {Keywords: superspeedable numbers, speedable numbers, regainingly approximable numbers, regular numbers, left-computable numbers}
}