Finite-difference approximation of the inverse Sturm–Liouville problem with frozen argument.

• Finite-difference approximation of the Sturm-Liouville problem with frozen argument is studied. • Theory of inverse spectral problems for the finite-difference approximation is developed. • Uniqueness theorems are proved and reconstruction algorithms are obtained for the degenerate and non-degenerate cases. • Numerical algorithm for solving the Sturm-Liouville inverse problem with frozen argument is developed. • Effectiveness of the algorithm is illustrated by numerical examples. This paper deals with the discrete system being the finite-difference approximation of the Sturm–Liouville problem with frozen argument. The inverse problem theory is developed for this discrete system. We describe the two principal cases: degenerate and non-degenerate. For these two cases, appropriate inverse problems statements are provided, uniqueness theorems are proved, and reconstruction algorithms are obtained. Moreover, the relationship between the eigenvalues of the continuous problem and its finite-difference approximation is investigated. We obtain the "correction terms" for approximation of the discrete problem eigenvalues by using the eigenvalues of the continuous problem. Relying on these results, we develop a numerical algorithm for recovering the potential of the Sturm–Liouville operator with frozen argument from a finite set of eigenvalues. The effectiveness of this algorithm is illustrated by numerical examples. [ABSTRACT FROM AUTHOR]