Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A local strategy for cleaning expanding cellular domains by simple
  robots   We present a strategy SEP for finite state machines tasked with cleaning a
cellular environment in which a contamination spreads. Initially, the
contaminated area is of height $h$ and width $w$. It may be bounded by four
monotonic chains, and contain rectangular holes. The robot does not know the
initial contamination, sensing only the eight cells in its neighborhood. It
moves from cell to cell, $d$ times faster than the contamination spreads, and
is able to clean its current cell. A speed of $d<\sqrt{2}(h+w)$ is in general
not sufficient to contain the contamination. Our strategy SEP succeeds if $d
\geq 3(h+w)$ holds. It ensures that the contaminated cells stay connected.
Greedy strategies violating this principle need speed at least $d \geq 4(h+w)$;
all bounds are up to small additive constants.

20
The categories of this paper are: acc-phys
24
The categories of this paper are: dg-ga
9
The categories of this paper are: nlin
37
The categories of this paper are: supr-con
14
The categories of this paper are: math-ph
4
The categories of this paper are: cond-mat
11
The categories of this paper are: hep-lat
32
The categories of this paper are: atom-ph
10
The categories of this paper are: q-bio
26
The categories of this paper are: bayes-an
2
The categories of this paper are: math
34
The categories of this paper are: chem-ph
31
The categories of this paper are: ao-sci
33
The categories of this paper are: plasm-ph
5
The categories of this paper are: gr-qc
25
The categories of this paper are: patt-sol