Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Interstellar Extinction Curve Variations Toward the Inner Milky Way: A
  Challenge to Observational Cosmology
14
The categories of this paper are: math-ph
2
The categories of this paper are: math
35
The categories of this paper are: mtrl-th
7
The categories of this paper are: hep-th
13
The categories of this paper are: quant-ph
11
The categories of this paper are: hep-lat
19
The categories of this paper are: eess
27
The categories of this paper are: comp-gas
30
The categories of this paper are: q-alg
18
The categories of this paper are: econ
28
The categories of this paper are: alg-geom
24
The categories of this paper are: dg-ga
5
The categories of this paper are: gr-qc
21
The categories of this paper are: adap-org
12
The categories of this paper are: nucl-th
9
The categories of this paper are: nlin