2012/09/03 by Marco Bramanti, Giovanni Cupini, Bramanti, Marco +5
Mathematics · #35B45 #35H10 #35K70 #42B20 #Analysis of PDEs (math.AP) #FOS: Mathematics #math.AP #msc:35B45 #msc:35H10 #msc:35K70 #msc:42B20
paper · pdf · doi:10.48550/arxiv.1209.0387
arxiv created 2012/09/03 · arxiv updated 2012/09/04
We consider a class of degenerate Ornstein-Uhlenbeck operators in ℝN, of the kind [A≡∑i,j=1^p0aij(x) ∂_xixj2+∑i,j=1Nbijxi∂_xj%] where (aij) is symmetric uniformly positive definite on ℝ^p0 (p0≤ N), with uniformly continuous and bounded entries, and (bij) is a constant matrix such that the frozen operator A_x0 corresponding to aij(x0) is hypoelliptic. For this class of operators we prove global Lp estimates (1<p<∞) of the kind:% [|∂_xixj2u|Lp(ℝ% N)≤ c|Au|Lp(ℝN)+|u|Lp(ℝ% N) for i,j=1,2,...,p0.] We obtain the previous estimates as a byproduct of the following one, which is of interest in its own:% [|∂_xixj2u|_Lp(ST)≤ c|Lu|_Lp(ST)+|u|_Lp(ST)] for any u∈ C0∞(ST), where ST is the strip ℝN×[-T,T], T small, and L is the Kolmogorov-Fokker-Planck operator% [L≡∑i,j=1^p0aij(x,t) ∂_xixj% 2+∑i,j=1Nbijxi∂_xj-∂t%] with uniformly continuous and bounded aij's.