  The PageRank is a widely used scoring function of networks in general and of
the World Wide Web graph in particular. The PageRank is defined for directed
graphs, but in some special cases applications for undirected graphs occur. In
the literature it is widely noted that the PageRank for undirected graphs are
proportional to the degrees of the vertices of the graph. We prove that
statement for a particular personalization vector in the definition of the
PageRank, and we also show that in general, the PageRank of an undirected graph
is not exactly proportional to the degree distribution of the graph: our main
theorem gives an upper and a lower bound to the L_1 norm of the difference of
the PageRank and the degree distribution vectors.
