Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Laser-induced ultrafast transport and demagnetization at the earliest
  time: First-principles and real-time investigation
32
The categories of this paper are: atom-ph
9
The categories of this paper are: nlin
3
The categories of this paper are: physics
18
The categories of this paper are: econ
10
The categories of this paper are: q-bio
14
The categories of this paper are: math-ph
12
The categories of this paper are: nucl-th
19
The categories of this paper are: eess
15
The categories of this paper are: nucl-ex
6
The categories of this paper are: astro-ph
26
The categories of this paper are: bayes-an
37
The categories of this paper are: supr-con
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
17
The categories of this paper are: q-fin