Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Indefinite least squares with a quadratic constraint   An abstract indefinite least squares problem with a quadratic constraint is
considered. This is a quadratic programming problem with one quadratic equality
constraint, where neither the objective nor the constraint are convex
functions. Necessary and sufficient conditions are found for the existence of
solutions.

37
The categories of this paper are: supr-con
0
The categories of this paper are: hep-ph
26
The categories of this paper are: bayes-an
33
The categories of this paper are: plasm-ph
28
The categories of this paper are: alg-geom
34
The categories of this paper are: chem-ph
30
The categories of this paper are: q-alg
19
The categories of this paper are: eess
1
The categories of this paper are: cs
13
The categories of this paper are: quant-ph
14
The categories of this paper are: math-ph
5
The categories of this paper are: gr-qc
20
The categories of this paper are: acc-phys
15
The categories of this paper are: nucl-ex
10
The categories of this paper are: q-bio
18
The categories of this paper are: econ