Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Landau's Theoretical Minimum, Landau's Seminar, ITEP in the Beginning of
  the 1950's   I recollect on the organization of the Landau school and describe the early
history of the ITEP Theory Department, as well as the history of creation of
famous Landau, Abrikosov, and Khalatnikov's papers, and Landau's papers on
P-parity violation and CP-conservation. The recollections carry an imprint of
the epoch long gone ..."

6
The categories of this paper are: astro-ph
22
The categories of this paper are: chao-dyn
15
The categories of this paper are: nucl-ex
5
The categories of this paper are: gr-qc
2
The categories of this paper are: math
30
The categories of this paper are: q-alg
3
The categories of this paper are: physics
31
The categories of this paper are: ao-sci
27
The categories of this paper are: comp-gas
13
The categories of this paper are: quant-ph
4
The categories of this paper are: cond-mat
8
The categories of this paper are: hep-ex
24
The categories of this paper are: dg-ga
16
The categories of this paper are: stat
32
The categories of this paper are: atom-ph
26
The categories of this paper are: bayes-an