Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Photoemission Evidence for Valence Fluctuations and Kondo Resonance in
  YbAl2
31
The categories of this paper are: ao-sci
20
The categories of this paper are: acc-phys
5
The categories of this paper are: gr-qc
19
The categories of this paper are: eess
3
The categories of this paper are: physics
37
The categories of this paper are: supr-con
2
The categories of this paper are: math
11
The categories of this paper are: hep-lat
7
The categories of this paper are: hep-th
22
The categories of this paper are: chao-dyn
14
The categories of this paper are: math-ph
36
The categories of this paper are: cmp-lg
6
The categories of this paper are: astro-ph
24
The categories of this paper are: dg-ga
30
The categories of this paper are: q-alg
17
The categories of this paper are: q-fin