  We show that the classical Hamburger moment problem can be included in the
spectral theory of generalized indefinite strings. Namely, we introduce the
class of Krein-Langer strings and show that there is a bijective correspondence
between moment sequences and this class of generalized indefinite strings. This
result can be viewed as a complement to the classical results of M. G. Krein on
the connection between the Stieltjes moment problem and Krein-Stieltjes strings
and I. S. Kac on the connection between the Hamburger moment problem and 2x2
canonical systems with Hamburger Hamiltonians.

Classical Analysis and ODEs;Spectral Theory