English

Independence in Arithmetic: The Method of $(\mathcal L, n)$-Models

Logic 2021-08-12 v3 Combinatorics

Abstract

I develop in depth the machinery of (L,n)(\mathcal L, n)-models originally introduced by Shelah and, independently in a slightly different form by Kripke. This machinery allows fairly routine constructions of true but unprovable sentences in PA\mathsf{PA}. I give two applications: 1. Shelah's alternative proof of the Paris-Harrington theorem, and 2. The independence over PA\mathsf{PA} of a new Π10\Pi^0_1 Ramsey theoretic statement about colorings of finite sequences of structures.

Cite

@article{arxiv.1906.04273,
  title  = {Independence in Arithmetic: The Method of $(\mathcal L, n)$-Models},
  author = {Corey Bacal Switzer},
  journal= {arXiv preprint arXiv:1906.04273},
  year   = {2021}
}

Comments

Anonymous referee found a gap in theorem 2.2. As such the main results of the paper need to be reconsidered

R2 v1 2026-06-23T09:49:30.327Z