Connectivity threshold in the Erdős-Rényi model (source code)

= Connectivity threshold in the Erdős-Rényi model

For every fixed $\varepsilon>0$,
$$
p\geq(1+\varepsilon)\frac{\log n}{n}
\Longrightarrow\mathbb P(G(n,p)\text{ is connected})\to1,
$$
whereas the probability tends to zero when $p\leq(1-\varepsilon)\log n/n$. Above the threshold a union bound excludes every component of size at most $n/2$; below it isolated vertices remain with high probability.