The classification problem for compact computable metric spaces

dc.citation.volume7921
dc.contributor.authorMelnikov A
dc.contributor.authorNies A
dc.coverage.spatialMilan, Italy
dc.date.available2013
dc.date.finish-date2013-07-05
dc.date.issued2013
dc.date.start-date2013-07-01
dc.description.abstractWe adjust methods of computable model theory to effective analysis. We use index sets and infinitary logic to obtain classification-type results for compact computable metric spaces. We show that every compact computable metric space can be uniquely described, up to isometry, by a computable Π3 formula, and that orbits of elements are uniformly given by computable Π2 formulas. We show that deciding if two compact computable metric spaces are isometric is a Π02Π20 complete problem within the class of compact computable spaces, which in itself is Π03Π30 . On the other hand, if there is an isometry, then ∅ ′′ can compute one. In fact, there is a set low relative to ∅ ′ which can compute an isometry. We show that the result can not be improved to ∅ ′. We also give further results for special classes of compact spaces, and for other related classes of Polish spaces.
dc.description.confidentialfalse
dc.format.extent320 - 328
dc.identifier.citationLecture Notes in Computer Science, 2013, 7921 pp. 320 - 328
dc.identifier.doi10.1007/978-3-642-39053-1_37
dc.identifier.elements-id239104
dc.identifier.harvestedMassey_Dark
dc.identifier.isbn9783642390524
dc.identifier.issn1611-3349
dc.publisherSpringer, Berlin, Heidelberg
dc.relation.isPartOfLecture Notes in Computer Science
dc.relation.urihttp://www.newton.ac.uk/files/preprints/ni13004_0.pdf
dc.sourceConference on Computability in Europe CiE 2013: The Nature of Computation. Logic, Algorithms, Applications
dc.titleThe classification problem for compact computable metric spaces
dc.typeconference
pubs.notesNot known
pubs.organisational-group/Massey University
pubs.organisational-group/Massey University/College of Sciences
pubs.organisational-group/Massey University/College of Sciences/School of Natural and Computational Sciences
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