Almost zero and high $\omega$-Turing degrees

TitleAlmost zero and high $\omega$-Turing degrees
Publication TypeJournal Article
Year of Publication2025
AuthorsSariev A
JournalAnnuaire de l’Université de Sofia “St. Kliment Ohridski”. Faculté de Mathématiques et Informatique
Volume112
Start Page137
Pagination137-152
ISSN1313-9215 (Print) 2603-5529 (Online)
Keywordsdefinability, degree structures, Turing reducibility
Abstract

We show that the class of the high degrees is definable in the terms of the almost zero degrees in the local substructure of the $\omega$-Turing degrees. Namely, we prove that a degree is high if and only if it bounds all almost zero degrees.

DOI10.60063/GSU.FMI.112.137-152
AttachmentSize
PDF icon 112-137-152.pdf583.64 KB