English

Shearing in some simple rank one theories

Logic 2023-07-13 v2

Abstract

Dividing asks about inconsistency along indiscernible sequences. In order to study the finer structure of simple theories without much dividing, the authors recently introduced shearing, which essentially asks about inconsistency along generalized indiscernible sequences. Here we characterize the shearing of the random graph. We then use shearing to distinguish between the random graph and the theories Tn,kT_{n,k}, the higher-order analogues of the triangle-free random graph. It follows that shearing is distinct from dividing in simple unstable theories, and distinguishes meaningfully between classes of simple unstable rank one theories. The paper begins with an overview of shearing, and includes open questions.

Keywords

Cite

@article{arxiv.2109.12642,
  title  = {Shearing in some simple rank one theories},
  author = {M. Malliaris and S. Shelah},
  journal= {arXiv preprint arXiv:2109.12642},
  year   = {2023}
}

Comments

[MiSh:1221] . This manuscript grew out of what was originally the last section of 1810.09604v2

R2 v1 2026-06-24T06:20:42.998Z