TURING DEGREE SPECTRA OF DIFFERENTIALLY CLOSED FIELDS.

The degree spectrum of a countable structure is the set of all Turing degrees of presentations of that structure. We show that every nonlow Turing degree lies in the spectrum of some differentially closed field (of characteristic 0, with a single derivation) whose spectrum does not contain the compu...

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Detalles Bibliográficos
Publicado en:Journal of Symbolic Logic Vol. 82; no. 1; pp. 1 - 26
Autores principales: Marker, David, Miller, Russell
Formato: Artículo
Publicado: Cambridge University Press Mar2017
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Acceso en línea:Ver este registro en EBSCOhost
Descripción
Sumario:The degree spectrum of a countable structure is the set of all Turing degrees of presentations of that structure. We show that every nonlow Turing degree lies in the spectrum of some differentially closed field (of characteristic 0, with a single derivation) whose spectrum does not contain the computable degree 0. Indeed, this is an equivalence, for we also show that if this spectrum contained a low degree, then it would contain the degree 0. From these results we conclude that the spectra of differentially closed fields of characteristic 0 are exactly the jump-preimages of spectra of automorphically nontrivial graphs.