2005/07/04 by Raul E. Curto, Lawrence A. Fialkow · 2 citations
Mathematics · #math.FA #msc:47A57 #msc:44A60 #msc:42A70 #msc:30A05
published as Integral Equations Operator Theory 52(2005), 181-218
arxiv created 2005/07/04 · arxiv updated 2009/12/01
Let Q(x,y)=0 be an hyperbola in the plane. Given real numbers β≡β2n)=\βij\i,j≥0,i+j≤2n, with β00>0, the truncated Q-hyperbolic moment problem for βentails finding necessary and sufficient conditions for the existence of a positive Borel measure μ, supported in Q(x,y)=0, such that βij=∫ yixj dμ(0≤ i+j≤2n). We prove that βadmits a Q-representing measure μ(as above) if and only if the associated moment matrix M(n)(β) is positive semidefinite, recursively generated, has a column relation Q(X,Y)=0, and the algebraic variety V(β) associated to βsatisfies cardV(β)≥\rankM(n)(β). In this case, rankM(n)≤2n+1; if rankM(n)≤2n, then βadmits a rankM(n)-atomic (minimal) Q-representing measure; if rankM(n)=2n+1, then βadmits a Q-representing measure μsatisfying 2n+1\leqcard suppμ≤2n+2.