This paper deals with the very weak solutions of A-harmonic equation divA(x, u(x))=0 (*)where the operator A satisfies the monotonicity inequality, the controllable growth condition and the homogeneity conditio...This paper deals with the very weak solutions of A-harmonic equation divA(x, u(x))=0 (*)where the operator A satisfies the monotonicity inequality, the controllable growth condition and the homogeneity condition. The extremum principle for very weak solutions of A-harmonic equation is derived by using the stability result of Iwaniec-Hodge decomposition: There exists an integrable exponent r1=r1(p,n,β/α)=1/2[p-α/100n^2β+√(p+α/100n^2β)^2-4α/100n^2β] such that if u(x) ∈ W^1,r(Ω)is a very weak solution of the A-harmonic equation (*), and m ≤ u(x) ≤ M on ЭΩ in the Sobolev sense, then m ≤u(x) 〈 M almost everywhere in Ω, provided that r 〉 r1. As a corollary, we prove that the O-Dirichlet boundary value problem {div_A(x, u(x))=0,u∈W0^1,r(Ω)of the A-harmonic equation has only zero solution if r 〉 r1.展开更多
文摘This paper deals with the very weak solutions of A-harmonic equation divA(x, u(x))=0 (*)where the operator A satisfies the monotonicity inequality, the controllable growth condition and the homogeneity condition. The extremum principle for very weak solutions of A-harmonic equation is derived by using the stability result of Iwaniec-Hodge decomposition: There exists an integrable exponent r1=r1(p,n,β/α)=1/2[p-α/100n^2β+√(p+α/100n^2β)^2-4α/100n^2β] such that if u(x) ∈ W^1,r(Ω)is a very weak solution of the A-harmonic equation (*), and m ≤ u(x) ≤ M on ЭΩ in the Sobolev sense, then m ≤u(x) 〈 M almost everywhere in Ω, provided that r 〉 r1. As a corollary, we prove that the O-Dirichlet boundary value problem {div_A(x, u(x))=0,u∈W0^1,r(Ω)of the A-harmonic equation has only zero solution if r 〉 r1.