Speaker: Alex W. N. Riasanovsky
Title: On the edit distance function of random graphs
Abstract: Given a hereditary property of graphs $\mathcal{H}$ and a $p\in [0,1]$, the edit distance function ${\rm ed}_{\mathcal{H}}(p)$ is asymptotically the maximum proportion of edge-additions plus edge-deletions applied to a graph of edge density $p$ sufficient to ensure that the resulting graph satisfies $\mathcal{H}$. The edit distance function is directly related to other well-studied quantities such as the speed function for $\mathcal{H}$ and the $\mathcal{H}$-chromatic number of a random graph.
Let $\mathcal{H}$ be the property of forbidding an Erd\H{o}s-R\'{e}nyi random graph $F\sim \mathbb{G}(n_0,p_0)$, and let $\varphi$ represent the golden ratio. In this paper, we show that if $p_0\in [1-1/\varphi,1/\varphi]$, then~\textbf{a.a.s.} as $n_0\to\infty$,
\begin{align*}
{\rm ed}_{\mathcal{H}}(p) = (1+o(1))\,\frac{2\log n_0}{n_0}
\cdot\min\left\{
\frac{p}{-\log(1-p_0)},
\frac{1-p}{-\log p_0}
\right\}.
\end{align*}
Moreover, this holds for $p\in [1/3,2/3]$ for any $p_0\in (0,1)$.