Self-embeddings of models of arithmetic; fixed points, small submodels, and extendability

Fuente: arXiv
Guardado en:
Detalles Bibliográficos
Autor principal: Bahrami, Saeideh
Formato: Preprint
Publicado: 2022
Materias:
Acceso en línea:
Etiquetas: Agregar Etiqueta
Sin Etiquetas, Sea el primero en etiquetar este registro!
_version_ 1866910704546611200
author Bahrami, Saeideh
author_facet Bahrami, Saeideh
contents In this paper we will show that for every cut $ I $ of any countable nonstandard model $ \mathcal{M} $ of $ \mathrm{I}Σ_{1} $, each $ I $-small $ Σ_{1} $-elementary submodel of $ \mathcal{M}$ is of the form of the set of fixed points of some proper initial self-embedding of $ \mathcal{M} $ iff $ I $ is a strong cut of $ \mathcal{M} $. Especially, this feature will provide us with some equivalent conditions with the strongness of the standard cut in a given countable model $ \mathcal{M} $ of $ \mathrm{I}Σ_{1} $. In addition, we will find some criteria for extendability of initial self-embeddings of countable nonstandard models of $ \mathrm{I}Σ_{1} $ to larger models.
format Preprint
id arxiv_https___arxiv_org_abs_2204_11284
institution arXiv
publishDate 2022
record_format arxiv
spellingShingle Self-embeddings of models of arithmetic; fixed points, small submodels, and extendability
Bahrami, Saeideh
Logic
In this paper we will show that for every cut $ I $ of any countable nonstandard model $ \mathcal{M} $ of $ \mathrm{I}Σ_{1} $, each $ I $-small $ Σ_{1} $-elementary submodel of $ \mathcal{M}$ is of the form of the set of fixed points of some proper initial self-embedding of $ \mathcal{M} $ iff $ I $ is a strong cut of $ \mathcal{M} $. Especially, this feature will provide us with some equivalent conditions with the strongness of the standard cut in a given countable model $ \mathcal{M} $ of $ \mathrm{I}Σ_{1} $. In addition, we will find some criteria for extendability of initial self-embeddings of countable nonstandard models of $ \mathrm{I}Σ_{1} $ to larger models.
title Self-embeddings of models of arithmetic; fixed points, small submodels, and extendability
topic Logic
url https://arxiv.org/abs/2204.11284