{ "id": "2007.05885", "version": "v1", "published": "2020-07-12T01:43:03.000Z", "updated": "2020-07-12T01:43:03.000Z", "title": "On Non-standard Models of Arithmetic with Uncountable Standard Systems", "authors": [ "Wei Wang" ], "comment": "6 pages", "categories": [ "math.LO" ], "abstract": "In 1960s, Dana Scott gave a recursion theoretic characterization of standard systems of countable non-standard models of arithmetic, i.e., collections of sets of standard natural numbers coded in non-standard models. Later, Knight and Nadel proved that Scott's characterization also applies to non-standard models of arithmetic with cardinality $\\aleph_1$. But the question, whether the limit on cardinality can be removed from the above characterization, remains a long standing question, known as the Scott Set Problem. This article presents two constructions of non-standard models of arithmetic with non-trivial uncountable standard systems. The first one leads to a new proof of the above theorem of Knight and Nadel, and the second proves the existence of models with non-trivial standard systems of cardinality the continuum. A partial answer to the Scott Set Problem under certain set theoretic hypothesis also follows from the second construction.", "revisions": [ { "version": "v1", "updated": "2020-07-12T01:43:03.000Z" } ], "analyses": { "subjects": [ "03C62", "03H15", "03D28", "03E50" ], "keywords": [ "arithmetic", "scott set problem", "non-trivial standard systems", "standard natural numbers", "cardinality" ], "note": { "typesetting": "TeX", "pages": 6, "language": "en", "license": "arXiv", "status": "editable" } } }