Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Run-and-tumble in a crowded environment: persistent exclusion process
  for swimmers   The effect of crowding on the run-and-tumble dynamics of swimmers such as
bacteria is studied using a discrete lattice model of mutually excluding
particles that move with constant velocity along a direction that is randomized
at a rate $\alpha$. In stationary state, the system is found to break into
dense clusters in which particles are trapped or stopped from moving. The
characteristic size of these clusters predominantly scales as $\alpha^{-0.5}$
both in 1D and 2D. For a range of densities, due to cooperative effects, the
stopping time scales as ${\cal T}_{1d}^{0.85}$ and as ${\cal T}_{2d}^{0.8}$,
where ${\cal T}_d$ is the diffusive time associated with the motion of cluster
boundaries. Our findings might be helpful in understanding the early stages of
biofilm formation.

30
The categories of this paper are: q-alg
24
The categories of this paper are: dg-ga
14
The categories of this paper are: math-ph
25
The categories of this paper are: patt-sol
8
The categories of this paper are: hep-ex
16
The categories of this paper are: stat
29
The categories of this paper are: funct-an
20
The categories of this paper are: acc-phys
32
The categories of this paper are: atom-ph
23
The categories of this paper are: solv-int
18
The categories of this paper are: econ
15
The categories of this paper are: nucl-ex
36
The categories of this paper are: cmp-lg
1
The categories of this paper are: cs
5
The categories of this paper are: gr-qc
33
The categories of this paper are: plasm-ph