Generalizations and Variants of the Largest Non-crossing Matching Problem in Random Bipartite Graphs

A two-rowed array αn = ( a1 a2 . . . an b1 b2 . . . bn ) is said to be in lexicographic order if ak ≤ ak+1 and bk ≤ bk+1 if ak = ak+1. A length ` (strictly) increasing subsequence of αn is a set of indices i1 < i2 < . . . < i` such that bi1 < bi2 < . . . < bi` . We are interested in the statistics of the length of the longest increasing subsequence of αn chosen according to Dn, for distinct families of distributions D = (Dn)n∈N, and when n goes to infinity. This general framework encompasses well studied problems such as the so called Longest Increasing Subsequence problem, the Longest Common Subsequence problem, problems concerning directed bond percolation models, among others. We define several natural families of distinct distributions and characterize the asymptotic behavior of the length of a longest increasing subsequence chosen according to them. In particular, we consider generalizations to d-rowed arrays as well as symmetry restricted two-rowed arrays.