3 citations · 7 across the 9 of their papers we have counts for
9 papers
Spectral Theory of Dirac Operators
Tigran Harutyunyan, Yuri Ashrafyan
The main issues of the spectral theory of Dirac operators are presented, namely: transformation operators, asymptotics of eigenvalues and eigenfunctions, description of symmetric a…
Inverse Sturm-Liouville problems with summable potential
Yuri Ashrafyan, Tigran Harutyunyan
We describe the necessary and sufficient conditions for two sequences {μ_n}^\infty_n=0 and {a_n}^\infty_n=0 to be correspondingly the set of eigenvalues and the set of norming cons…
Gradient of eigenvalues of Dirac operators and its applications
Tigran Harutyunyan, Yuri Ashrafyan
For Dirac operators, which have discrete spectra, the concept of eigenvalues gradient is given and formulae for this gradients are obtained in terms of normalized eigenfunctions. I…
Isospectral Dirac operators
Yuri Ashrafyan, Tigran Harutyunyan
We give the description of self-adjoint regular Dirac operators, on , with the same spectra.
Dirac operator with linear potential and its perturbations
Yuri A. Ashrafyan, Tigran N. Harutyunyan
We prove that canonical Dirac expression with linear potential generates operators on axis and half axis, for which we can find the eigenvalues and eigenfunctions in explicit form.…
Inverse Sturm-Liouville problems with fixed boundary conditions
Tigran Harutyunyan, Yuri Ashrafyan
Necessary and sufficient conditions for two sequences and to be the spectral data for a certain Sturm-Liouville problem are well know…
On the "movement" of the zeros of eigenfunctions of the Sturm-Liouville problem
Tigran Harutyunyan, Avetik Pahlevanyan, Yuri Ashrafyan
We study the dependence of the zeros of eigenfunctions of Sturm-Liouville problem on the parameters that define the boundary conditions. As a corollary, we obtain Sturm oscillation…
Riesz bases generated by the spectra of Sturm-Liouville problems
Tigran Harutyunyan, Avetik Pahlevanyan, Anna Srapionyan
Let be the spectra of a Sturm-Liouville problem on . We investigate the question: Do the systems or $\{\sin(λ_n x)…
On the norming constants of the Sturm-Liouville problem
Tigran Harutyunyan, Avetik Pahlevanyan
We derive new asymptotic formulae for the norming constants of Sturm-Liouville problem with summable potentials, which generalize and make more precise previously known formulae. M…