The Maximum and Minimum Degree of the Random γ-uniform γ-partite Hypergraphs

In this paper we consider the random r-uniform r-partite hypergraph model H（n1, n2,…, nr; n, p） which consists of all the r-uniform r-partite hypergraphs with vertex partition {V1,V2,…, Vr} where ｜Vi｜ = ni = ni（n） （1 ≤ i ≤ r） are positive integer-valued functions on n with n1 ＋n2 ＋… ＋nr =n, and each r-subset containing exactly one element in Vi （1 ≤ i ≤ r） is chosen to be a hyperedge of Hp ∈H（n1,n2,…,nr;n,p） with probability p = p（n）, all choices being independent. Let △V1 = △V1 （H） and δv1 = δv1（H） be the maximum and minimum degree of vertices in V1 of H, respectively; Xd,V1 = Xd,V1 （H）, Yd,V1 = Yd,V1 （H）, Zd,V1 = Zd,V1 （H） and Zc,d,V1=Zc,d,V1 （H） be the number of vertices in V1 of H with degree d, at least d, at most d, and between c and d, respectively. In this paper we obtain that in the space H（n1, n2,…, nr; n,p）, Xd,V1, Yd,V1, Zd,V1, and Zc,d,V1all have asymptotically Poisson distributions. We also answer the following two questions. What is the range of p that there exists a function D（n） such that in the space H（n1, n2,…,nr; n, p）, lim n→＋∞ P（△v1 = D（n）） = 1？ What is the range of p such that a.e., Hp ∈ H（n1,n2,...,nr;n,p） has a unique vertex in V1 with degree Av1（Hp）？ Both answers are p = o（logn1/N）, where N = r ∏ i=2 ni. The corresponding problems on δv1（Hp） also are considered, and we obtained the answers are p ≤ （1＋o（1））（logn1/N） andp=o （log n1/N）, respectively.