Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Unbiased estimation of an optical loss at the ultimate quantum limit
  with twin-beams
17
The categories of this paper are: q-fin
4
The categories of this paper are: cond-mat
28
The categories of this paper are: alg-geom
16
The categories of this paper are: stat
5
The categories of this paper are: gr-qc
35
The categories of this paper are: mtrl-th
10
The categories of this paper are: q-bio
1
The categories of this paper are: cs
15
The categories of this paper are: nucl-ex
24
The categories of this paper are: dg-ga
36
The categories of this paper are: cmp-lg
2
The categories of this paper are: math
37
The categories of this paper are: supr-con
19
The categories of this paper are: eess
30
The categories of this paper are: q-alg
31
The categories of this paper are: ao-sci