Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Effect of the orientational relaxation on the collective motion of
  patterns formed by self-propelled particles   We investigate the collective behavior of self-propelled particles (SPPs)
undergoing competitive processes of pattern formation and rotational relaxation
of their self-propulsion velocities. In full accordance with previous work, we
observe transitions between different steady states of the SPPs caused by the
intricate interplay among the involved effects of pattern formation,
orientational order, and coupling between the SPP density and orientation
fields. Based on rigorous analytical and numerical calculations, we prove that
the rate of the orientational relaxation of the SPP velocity field is the main
factor determining the steady states of the SPP system. Further, we determine
the boundaries between domains in the parameter plane that delineate
qualitatively different resting and moving states. In addition, we analytically
calculate the collective velocity $\vec{v}$ of the SPPs and show that it
perfectly agrees with our numerical results. We quantitatively demonstrate that
$\vec{v}$ does not vanish upon approaching the transition boundary between the
moving pattern and homogeneous steady states.

9
The categories of this paper are: nlin
26
The categories of this paper are: bayes-an
23
The categories of this paper are: solv-int
21
The categories of this paper are: adap-org
37
The categories of this paper are: supr-con
20
The categories of this paper are: acc-phys
16
The categories of this paper are: stat
29
The categories of this paper are: funct-an
17
The categories of this paper are: q-fin
19
The categories of this paper are: eess
2
The categories of this paper are: math
0
The categories of this paper are: hep-ph
12
The categories of this paper are: nucl-th
22
The categories of this paper are: chao-dyn
18
The categories of this paper are: econ
31
The categories of this paper are: ao-sci