Abstract
In a bounded open subset ΩâRn, we study Dirichlet problems with elliptic systems, involving a finite Radon measure ÎŒ on Rn with values into RN, defined by{âdivA(x,u(x),Du(x))=ÎŒ in Ω,u=0 on âΩ, where Aiα(x,y,Ο)=âÎČ=1Nâj=1nai,jα,ÎČ(x,y)ΟjÎČ with αâ{1,âŠ,N} the equation index. We prove the existence of a (distributional) solution u:ΩâRN, obtained as the limit of approximations, by assuming: (i) that coefficients ai,jα,ÎČ are bounded CarathĂ©odory functions; (ii) ellipticity of the diagonal coefficients ai,jα,α; and (iii) smallness of the quadratic form associated to the off-diagonal coefficients ai,jα,ÎČ (i.e. αâ ÎČ) verifying a r-staircase support condition with r>0. Such a smallness condition is satisfied, for instance, in each one of these cases: (a) ai,jα,ÎČ=âaj,iÎČ,α (skew-symmetry); (b) |aα,ÎČi,j| is small; (c) ai,jα,ÎČ may be decomposed into two parts, the first enjoying skew-symmetry and the second being small in absolute value. We give an example that satisfies our hypotheses but does not satisfy assumptions introduced in previous works. A Brezis's type nonexistence result is also given for general (smooth) elliptic-hyperbolic systems.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have