2022/08/31 by Maz'ya, Vladimir, McOwen, Robert · 1 citation
#35A08 (Primary) #35B40 #35J15 (Secondary) #Analysis of PDEs (math.AP) #FOS: Mathematics
paper · doi:10.48550/arxiv.2209.00058
For n≥ 3, we study the existence and asymptotic properties of the fundamental solution for elliptic operators in nondivergence form, \mathcal L(x,∂x)=aij(x)∂i∂j+bk(x)∂k, where the aij have modulus of continuity ω(r) satisfying the square-Dini condition and the bk are allowed mild singularities of order r-1ω(r). A singular integral is introduced that controls the existence of the fundamental solution. We give examples that show the singular drift bk∂k may act as a perturbation that does not dramatically change the fundamental solution of \mathcal Lo=aij∂i∂j, or it could change an operator \mathcal Lo that does not have a fundamental solution to one that does.