The math behind google page rank

I came across this interesting article on another site that linked to an article written by David Austin of The American Mathematical Society who wrote about the math behind google page rank.

David writes: "Here's how the PageRank is determined. Suppose that page P_j has l_j links. If one of those links is to page P_i, then P_j will pass on 1/l_j of its importance to P_i. The importance ranking of P_i is then the sum of all the contributions made by pages linking to it. That is, if we denote the set of pages linking to P_i by B_i, then ..." - (makes complete since to me!)

Click here to learn more about this interesting theory and extremely complex calculation.