85 citations · 210 across the 20 of their papers we have counts for
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Special N-extremal solutions to indeterminate moment problems
Christian Berg, Ryszard Szwarc
For an N-extremal solution to an indeterminate moment problem it is known by a theorem of M. Riesz that the measure is determinate. For we show by c…
Indeterminate Jacobi operators II
Christian Berg, Ryszard Szwarc
We consider the Jacobi operator (T,D(T)) associated with an indeterminate Hamburger moment problem, and present countable subsets S of the domain D(T) such that span(S) is dense in…
Indeterminate Jacobi operators
Christian Berg, Ryszard Szwarc
We consider the Jacobi operator (T,D(T)) associated with an indeterminate Hamburger moment problem, i.e., the operator in defined as the closure of the Jacobi matrix actin…
Self-adjoint operators associated with Hankel moment matrices
Christian Berg, Ryszard Szwarc
In a paper from 2016 D. R. Yafaev initiated a study of closable Hankel forms associated with the moments of a positive measure with infinite support on the real line. If $m…
Closable Hankel operators and moment problems
Christian Berg, Ryszard Szwarc
In a paper from 2016 D. R. Yafaev considers Hankel operators associated with Hamburger moment sequences q_n and claims that the corresponding Hankel form is closable if and only if…
Inhomogeneous Jacobi matrices on trees
Ryszard Szwarc
We study Jacobi matrices on trees with one end at inifinity. We show that the defect indices cannot be greater than 1 and give criteria for essential selfadjointness. We construct…