On the QALE geometry of Nakajima's metric
  We show that on Hilbert scheme of $n$ points on $\C^2$, the hyperk\"ahler metric construsted by H. Nakajima via hyperk\"ahler reduction is the Quasi-Asymptotically Locally Euclidean (QALE in short) metric constructed by D. Joyce. 
Gilles Carron (LMJL)