The Schröder-Bernstein property for a-saturated models
نویسندگان
چکیده
A first-order theory T has the Schröder-Bernstein (SB) property if any pair of elementarily bi-embeddable models are isomorphic. We prove that T has an expansion by constants that has the SB property if and only if T is superstable and non-multidimensional. We also prove that among superstable theories T , the class of a-saturated models of T has the SB property if and only if T has no nomadic types. Partially supported by a grant from the Facultad de Ciencias, Universidad de los Andes, and by a travel grant from MSRI to attend the BIRS workshop on Neostability Theory (January 29-February 4, 2012). Partially supported by NSF grant DMS-0901336.
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