Representing Measures on the Royden Boundary for Solutions of Δu=Pu on a Riemannian Manifold
<p>Consider the Royden compactification R* of a Riemannian n-manifold R, Γ = R*\R its Royden boundary, Δ its harmonic boundary and the elliptic differential equation Δu = Pu, P ≥ 0 on R. A regular Borel measure m<sup>P</sup> can be constructed on Γ with support equal to the closur...
Summary: | <p>Consider the Royden compactification R* of a Riemannian n-manifold R, Γ = R*\R its Royden boundary, Δ its harmonic boundary and the elliptic differential equation Δu = Pu, P ≥ 0 on R. A regular Borel measure m<sup>P</sup> can be constructed on Γ with support equal to the closure of Δ<sup>P</sup> = {q ϵ Δ : q has a neighborhood U in R* with <sub>U</sub><sup>ʃ</sup><sub>ᴖR</sub><sup>P ˂ ∞ </sup>}. Every enegy-finite solution to u (i.e. E(u) = D(u) + <sup>ʃ</sup><sub>R</sub>u<sup>2</sup>P ˂ ∞, where D(u) is the Dirichlet integral of u) can be represented by u(z) = <sup>ʃ</sup><sub>Γ</sub>u(q)K(z,q)dm<sup>P</sup>(q) where K(z,q) is a continuous function on <sup>Rx</sup> Γ . A <sub>P</sub><sup>~</sup><sub>E</sub>-function is a nonnegative solution which is the infimum of a downward directed family of energy-finite solutions. A nonzero <sub>P</sub><sup>~</sup><sub>E</sub>-function is called <sub>P</sub><sup>~</sup><sub>E</sub>-minimal if it is a constant multiple of every nonzero <sub>P</sub><sup>~</sup><sub>E</sub>-function dominated by it. <u>THEOREM</u>. There exists a <sub>P</sub><sup>~</sup><sub>E</sub>-minimal function if and only if there exists a point in q ϵ Γ such that m<sup>P</sup>(q) > 0. <u>THEOREM</u>. For q ϵ Δ<sup>P</sup> , m<sup>P</sup>(q) > 0 if and only if m<sup>0</sup>(q) > 0 .</p> |
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