Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: The Cosmological Constant $\Lambda$, the Age of the Universe and Dark
  Matter: Clues from the Ly$\alpha$-Forest
17
The categories of this paper are: q-fin
27
The categories of this paper are: comp-gas
11
The categories of this paper are: hep-lat
37
The categories of this paper are: supr-con
25
The categories of this paper are: patt-sol
7
The categories of this paper are: hep-th
28
The categories of this paper are: alg-geom
35
The categories of this paper are: mtrl-th
29
The categories of this paper are: funct-an
34
The categories of this paper are: chem-ph
16
The categories of this paper are: stat
9
The categories of this paper are: nlin
18
The categories of this paper are: econ
3
The categories of this paper are: physics
36
The categories of this paper are: cmp-lg
15
The categories of this paper are: nucl-ex