Algorithms for calculating eigenvalues of discrete semi-bounded operators defined on quantum graphs of star type with variable edges

The article develops algorithms for calculating the eigenvalues of initial-boundary value problems for differential equations defined on a star graph with variable edges. Numerical experiments on calculating the eigenvalues of the problems under study were carried out in the Maple mathematical environment. The developed technique can be transferred to boundary value problems for any discrete semi-bounded operators and will allow developing algorithms for solving inverse spectral problems defined on quantum graphs with variable edges.