Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Spectral analysis for one class of second-order indefinite
  non-self-adjoint differential operator pencil   The inverse problem for the differential operator pencil with complex
periodic potential and discontinuous coefficients on the axis is studied. Main
characteristics of the fundamental solutions are investigated, the spectrum of
the operator is studied. We give formulation of the inverse problem, prove a
uniqueness theorem and provide a constructive procedure for the solution of the
inverse problem

34
The categories of this paper are: chem-ph
6
The categories of this paper are: astro-ph
9
The categories of this paper are: nlin
11
The categories of this paper are: hep-lat
8
The categories of this paper are: hep-ex
18
The categories of this paper are: econ
15
The categories of this paper are: nucl-ex
27
The categories of this paper are: comp-gas
16
The categories of this paper are: stat
31
The categories of this paper are: ao-sci
4
The categories of this paper are: cond-mat
28
The categories of this paper are: alg-geom
37
The categories of this paper are: supr-con
32
The categories of this paper are: atom-ph
13
The categories of this paper are: quant-ph
35
The categories of this paper are: mtrl-th