We will show that
if u0 ∈ Llocp(R2) for some constant p > 1, 0 ≤ u0 ≤ (2∕β)|x|−2, and
u0(x) − (2∕β)(|x|2 + k′)−1 ∈ L1(R2) for some constants β > 0, k′ > 0, then the
rescaled function w(x,t) = e2βtu(eβtx,t) of the solution u of the Ricci flow equation
ut = Δlog u, u > 0, in R2 × (0,∞), u(x,0) = u0(x) in R2, will converge
to ϕβ,k0(x) = (2∕β)(|x|2 + k0)−1 in L1(R2) as t →∞ where k0 > 0 is a
constant chosen such that ∫
R2(u0 − ϕβ,k0)dx = 0. Moreover if u0 satisfies in
addition the condition ϕβ,k1 ≤ u0 ≤ ϕβ,k2 for some constants k1 > 0, k2 > 0,
then w will converge uniformly to ϕβ,k0 on every compact subset of R2 as
t →∞.
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