In this paper we study the global existence and asymptotic behaviour of solutions tout=Δ log ufor the Cauchy initial value problem inRn. We prove that ifn 3, then every solution satisfies ∫Rn up(x, t) dx=∞ for any 1
n/2. Hence, we extend a previous result of Vazquez [19] which claims that ∫Rn u dx=∞ for 0