References
- Rodman L. An introduction to operator polynomials. Basel: Birkhäuser Verlag; 1989.
- Shkalikov AA, Tretter C. Spectral analysis for linear pencils N – λPof ordinary differential operators. Math. Nachr. 1996;179:275–305.
- Grűnbaum FA, Vinet L, Zhedanov A. Linear operator pencils on Lie algebras and Laurent biorthogonal polynomials. J. Phys. A: Math. Gen. 2004;37:7711–7725.
- Tretter C. Linear operator pencils A ₋ Bwith discrete spectrum Integr. Equ. Oper. Theory. 2000;37:357–373.
- Cojuhari PA. Estimates of the discrete spectrum of a linear operator pencil. J. Math. Anal. Appl. 2007;326:1394–1409.
- Kurbatova IV. A Banach algebra associated with a linear operator pencil. Mat. Zametki. 2009;86: 394–401. Russian; translation in Math. Notes. 2009;86:361–367.
- Bairamov E, Cakar O, Krall AM. Spectral properties, including spectral singularities, of a quadratic pencil of Schrödinger operators on the whole real axis. Quaest. Math. 2003;26:15–30.
- Efendiev RF. Spectral analysis for one class of second-order indefinite non-self-adjoint differential operator pencil. Appl. Anal. 2011;90:1837–1849.
- Gil’ MI. On bounds for spectra of operator pencils in a Hilbert space. Acta Math. Sin. (Engl. Ser.). 2003;19:313–326.
- Gil’ MI. Bounds for the spectrum of analytic quasinormal operator pencils. Commun. Contemp. Math. 2003;5:101–118.
- Gil MI. Sums of characteristic values of compact operator pencils. J. Math. Anal. Appl. 2008;338:1469–1476.
- Hasanov M. An approximation method in the variational theory of the spectrum of operator pencils. Acta Appl. Math. 2002;71:117–126.
- Manafov MD, Kablan A. On a quadratic pencil of differential operators with periodic generalized potential. Int. J. Pure Appl. Math. 2009;50:515–522.
- Yakubov Y. Fold completeness of a system of root vectors of a system of unbounded polynomial operator pencils in Banach spaces. I. Abstract theory. J. Math. Pures Appl. (9). 2009;92:263–275.
- Gil’ MI. Operator functions and localization of spectra. Berlin: Springer-Verlag; 2003.
- Gohberg I, Krein MG. Introduction to the theory of linear nonselfadjoint operators. Vol. 18, Translations of mathematical monographs. Providence (RI): American Mathematical Society; 1969.