Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Hydrodynamic Model for the System of Self Propelling Particles with
  Conservative Kinematic Constraints; Two dimensional stationary solutions   We consider a continuum model for the dynamics of systems of self propelling
particles with kinematic constraints on the velocities. The model aims to be
analogous to a discrete algorithm used in works by T. Vicsek et al. In this
paper we prove that the only types of the stationary planar solutions in the
model are either of translational or axial symmetry of the flow. Within the
proposed model we differentiate between finite and infinite flocking behavior
by the finiteness of the kinetic energy functional.

30
The categories of this paper are: q-alg
32
The categories of this paper are: atom-ph
21
The categories of this paper are: adap-org
15
The categories of this paper are: nucl-ex
24
The categories of this paper are: dg-ga
5
The categories of this paper are: gr-qc
35
The categories of this paper are: mtrl-th
7
The categories of this paper are: hep-th
20
The categories of this paper are: acc-phys
4
The categories of this paper are: cond-mat
17
The categories of this paper are: q-fin
18
The categories of this paper are: econ
34
The categories of this paper are: chem-ph
10
The categories of this paper are: q-bio
36
The categories of this paper are: cmp-lg
23
The categories of this paper are: solv-int