External automorphisms of ultraproducts of finite models
نویسندگان
چکیده
Let L be a finite first-order language and 〈Mn | n < ω〉 be a sequence of finite L-models containing models of arbitrarily large finite cardinality. If the intersection of less than continuum-many dense open subsets of Cantor Space 2 is non-empty, then there is a non-principal ultrafilter U over ω such that the corresponding ultraproduct Q U Mn is infinite and has an automorphism that is not induced by an element of Q
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ورودعنوان ژورنال:
- Arch. Math. Log.
دوره 51 شماره
صفحات -
تاریخ انتشار 2012