On unsuperstable theories in GDST

Abstract

We study the $\kappa$-Borel-reducibility of isomorphism relations of complete first order theories by using coloured trees. Under some cardinality assumptions, we show the following: For all theories T and T', if T is classifiable and T' is unsuperstable, then the isomorphism of models of T' is strictly above the isomorphism of models of T with respect to $\kappa$-Borel-reducibility.

References in corpus (1)

• The isomorphism relation of theories with S-DOP in generalized Baire spaces