Spectra of Atomic Theories
Uri Andrews, Julia F. Knight · Journal of Symbolic Logic · 2009
Abstract For a countable structure , the spectrum is the set of Turing degrees of isomorphic copies of . For a complete elementary first order theory T, the spectrum is the set of Turing degrees of models of T. We answer a question from [1] by showing that there is an atomic theory T whose spectrum does not match the spectrum of any structure.