Stability of eigenvalues of singular integral equations

A complex number $\lambda$ is called the stable eigenvalue of an operator $A$ iff $\operatorname{Ker}(A-\lambda I+C)\ne\{\mathbb{O}\}$ for anv coropact operator $C$. In. the article the description is given of the stable- eigenvalues for a class of operators including some classical ones. Besides, there is discussed the stability of the whole point spectrum and the mutual stability of different eigenvalues.