Simple structures with complex symmetry

V. Harizanov ; R. Miller ; A. S. Morozov

Algebra i logika, Tome 49 (2010) no. 1, pp. 98-134.

Résumé

We define the automorphism spectrum of a computable structure $\mathcal M$, a complexity measure of the symmetries of $\mathcal M$, and prove that certain sets of Turing degrees can be realized as automorphism spectra, while certain others cannot.

Détail

Keywords: complexity measure of symmetries of computable structure, automorphism spectrum.

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