“…We mention here only [8,12,19,23,28] The aim of our work is the investigation of the class of spectralizable operators. Spectralizable operators arise in many different problems, see, e.g., [7,14,15,16,31,32,33]. We mention that the term spectralizable was used first in [30] in a very special setting, where, in particular, one can find an example of a non-self-adjoint difference operator with a self-adjoint square.…”