We characterize the rate of convergence of a converging volume-normalized
Yamabe flow in terms of Morse theoretic properties of the limiting metric. If
the limiting metric is an integrable critical point for the Yamabe functional
(for example, this holds when the critical point is non-degenerate), then we
show that the flow converges exponentially fast. In general, we make use of a
suitable Lojasiewicz-Simon inequality to prove that the slowest the flow will
converge is polynomially. When the limit metric satisfies an Adams-Simon type
condition we prove that there exist flows converging to it exactly at a
polynomial rate. We conclude by constructing explicit examples to show that
this does occur; these seem to be the first examples of a slowly converging
solution to a geometric flow.Comment: Some corrections. To appear in Geometry & Topolog