Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Droplet-like Fermi surfaces in the anti-ferromagnetic phase of
  EuFe$_2$As$_2$, an Fe-pnictide superconductor parent compound
13
The categories of this paper are: quant-ph
22
The categories of this paper are: chao-dyn
9
The categories of this paper are: nlin
17
The categories of this paper are: q-fin
26
The categories of this paper are: bayes-an
30
The categories of this paper are: q-alg
21
The categories of this paper are: adap-org
33
The categories of this paper are: plasm-ph
36
The categories of this paper are: cmp-lg
25
The categories of this paper are: patt-sol
8
The categories of this paper are: hep-ex
7
The categories of this paper are: hep-th
12
The categories of this paper are: nucl-th
2
The categories of this paper are: math
19
The categories of this paper are: eess
11
The categories of this paper are: hep-lat