Autostability spectra for decidable structures. / Bazhenov, Nikolay.
In: Mathematical Structures in Computer Science, Vol. 28, No. 3, 01.03.2018, p. 392-411.Research output: Contribution to journal › Article › peer-review
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TY - JOUR
T1 - Autostability spectra for decidable structures
AU - Bazhenov, Nikolay
PY - 2018/3/1
Y1 - 2018/3/1
N2 - We study autostability spectra relative to strong constructivizations (SC-autostability spectra). For a decidable structure , the SC-autostability spectrum of is the set of all Turing degrees capable of computing isomorphisms among arbitrary decidable copies of . The degree of SC-autostability for is the least degree in the spectrum (if such a degree exists). We prove that for a computable successor ordinal α, every Turing degree c.e. in and above 0 (α) is the degree of SC-autostability for some decidable structure. We show that for an infinite computable ordinal β, every Turing degree c.e. in and above 0 (2β+1) is the degree of SC-autostability for some discrete linear order. We prove that the set of all PA-degrees is an SC-autostability spectrum. We also obtain similar results for autostability spectra relative to n-constructivizations.
AB - We study autostability spectra relative to strong constructivizations (SC-autostability spectra). For a decidable structure , the SC-autostability spectrum of is the set of all Turing degrees capable of computing isomorphisms among arbitrary decidable copies of . The degree of SC-autostability for is the least degree in the spectrum (if such a degree exists). We prove that for a computable successor ordinal α, every Turing degree c.e. in and above 0 (α) is the degree of SC-autostability for some decidable structure. We show that for an infinite computable ordinal β, every Turing degree c.e. in and above 0 (2β+1) is the degree of SC-autostability for some discrete linear order. We prove that the set of all PA-degrees is an SC-autostability spectrum. We also obtain similar results for autostability spectra relative to n-constructivizations.
KW - STRONG CONSTRUCTIVIZATIONS
KW - BOOLEAN-ALGEBRAS
KW - INDEX SETS
KW - COMPUTABLE CATEGORICITY
KW - RECURSIVE STRUCTURES
KW - HYPERARITHMETICAL DEGREES
KW - LINEAR-ORDERINGS
KW - MODELS
KW - COMPLEXITY
KW - STABILITY
UR - http://www.scopus.com/inward/record.url?scp=84991253027&partnerID=8YFLogxK
U2 - 10.1017/S096012951600030X
DO - 10.1017/S096012951600030X
M3 - Article
AN - SCOPUS:84991253027
VL - 28
SP - 392
EP - 411
JO - Mathematical Structures in Computer Science
JF - Mathematical Structures in Computer Science
SN - 0960-1295
IS - 3
ER -
ID: 12177864