Rank-width of random graphs

Rank‐width of a graph G, denoted by rw(G), is a width parameter of graphs introduced by Oum and Seymour [J Combin Theory Ser B 96 (2006), 514–528]. We investigate the asymptotic behavior of rank‐width of a random graph G(n, p). We show that, asymptotically almost surely, (i) if p∈(0, 1) is a constant, then rw(G(n, p)) = ⌈n/3⌉−O(1), (ii) if urn:x-wiley:03649024:jgt20620:equation:jgt20620-math-0001, then rw(G(n, p)) = ⌈1/3⌉−o(n), (iii) if p = c/n and c>1, then rw(G(n, p))⩾rn for some r = r(c), and (iv) if p⩽c/n and c81, then rw(G(n, p))⩽2. As a corollary, we deduce that the tree‐width of G(n, p) is linear in n whenever p = c/n for each c>1, answering a question of Gao [2006]