On dimension of posets excluding a standard example

Abstract

We prove that for every integer $d \geq 3$, there exists $\alpha<1$ such that the maximum dimension of an $n$-element poset containing no standard example of order $d$ as an induced subposet is $\mathcal{O}_d(n^\alpha)$. For $d=3$, we obtain an upper bound $\mathcal{O}(n^{2/3}\log n)$, while we also construct a family of $S_3$-free posets with dimension $\Omega(n^{1/3}/\log n)$. The proofs were found by OpenAI's ChatGPT-6 Astra.