Random Intersection Graphs G(n,m,p) is a class of random graphs
in which each of n vertices randomly and independently chooses
some elements from a universal set S, of cardinality
m. Each element is chosen with probability p. Two vertices are joined
by an edge iff their chosen element sets intersect. Given n, m so that
m=n^a, for any real a different than one, we establish here tight lower
bounds p_0(n,m), on the value of p, as a function of n and m, above which
the graph G_{n,m,p} is almost certainly Hamiltonian.
The bounds are tight in the sense that if p is asymptotically
smaller than p_0(n,m) then G(n,m,p) almost certainly has a vertex of
degree less than 2. The proof involves new coupling
techniques that allow us to circumvent the edge dependencies
in the random intersection graph model.
The results strongly support the existence of a threshold for
Hamiltonicity in G(n,m,p).-