Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Comment on "Novel type of phase transition in a system of self-driven
  particles"   This paper uncovers a pitfall in the phase transition mechanism of Vicsek et
al. [Phys. Rev. Lett. 75, 1226 (1995)] which occurs with fairly high
probability and leads to complete breakdown of the model dynamics.

33
The categories of this paper are: plasm-ph
8
The categories of this paper are: hep-ex
28
The categories of this paper are: alg-geom
10
The categories of this paper are: q-bio
32
The categories of this paper are: atom-ph
31
The categories of this paper are: ao-sci
6
The categories of this paper are: astro-ph
7
The categories of this paper are: hep-th
11
The categories of this paper are: hep-lat
21
The categories of this paper are: adap-org
19
The categories of this paper are: eess
20
The categories of this paper are: acc-phys
22
The categories of this paper are: chao-dyn
24
The categories of this paper are: dg-ga
26
The categories of this paper are: bayes-an
16
The categories of this paper are: stat