Turing degrees of isomorphism types of geometric objects
  We initiate the computability-theoretic study of ringed spaces and schemes. In particular, we show that any Turing degree may occur as the least degree of an isomorphic copy of a structure of these kinds. We also show that these structures may fail to have a least degree. 
Wesley Calvert, Valentina Harizanov and Alexandra Shlapentokh
math.LO math.AG