A standard model of Peano arithmetic with no conservative elementary extension

The principal result of this paper answers a long-standing question in the model theory of arithmetic [KS, Question 7] by showing that there exists an uncountable arithmetically closed family A of subsets of the set of natural numbers such that the expansion A := (, +,

• Type: Journal
• Year: 2008
• Where: APAL
• Authors: Ali Enayat
• Keywords: APAL 2008, Conservative Elementary Extension, Elementary Extension, Long-standing Question