%0 Journal Article %T Classification of solutions to the higher order Liouville's equation on R^{2m} %A Luca Martinazzi %J Mathematics %D 2008 %I arXiv %R 10.1007/s00209-008-0419-1 %X We classify the solutions to the equation (- \Delta)^m u=(2m-1)!e^{2mu} on R^{2m} giving rise to a metric g=e^{2u}g_{R^{2m}} with finite total $Q$-curvature in terms of analytic and geometric properties. The analytic conditions involve the growth rate of u and the asymptotic behaviour of \Delta u(x) as |x|\to \infty. As a consequence we give a geometric characterization in terms of the scalar curvature of the metric e^{2u}g_{R^{2m}} at infinity, and we observe that the pull-back of this metric to $S^{2m}$ via the stereographic projection can be extended to a smooth Riemannian metric if and only if it is round. %U http://arxiv.org/abs/0801.2729v1