Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Universality of two-dimensional critical cellular automata   We study the class of monotone, two-state, deterministic cellular automata,
in which sites are activated (or 'infected') by certain configurations of
nearby infected sites. These models have close connections to statistical
physics, and several specific examples have been extensively studied in recent
years by both mathematicians and physicists. This general setting was first
studied only recently, however, by Bollob\'as, Smith and Uzzell, who showed
that the family of all such 'bootstrap percolation' models on $\mathbb{Z}^2$
can be naturally partitioned into three classes, which they termed subcritical,
critical and supercritical.
  In this paper we determine the order of the threshold for percolation
(complete occupation) for every critical bootstrap percolation model in two
dimensions. This 'universality' theorem includes as special cases results of
Aizenman and Lebowitz, Gravner and Griffeath, Mountford, and van Enter and
Hulshof, significantly strengthens bounds of Bollob\'as, Smith and Uzzell, and
complements recent work of Balister, Bollob\'as, Przykucki and Smith on
subcritical models.

8
The categories of this paper are: hep-ex
4
The categories of this paper are: cond-mat
7
The categories of this paper are: hep-th
15
The categories of this paper are: nucl-ex
31
The categories of this paper are: ao-sci
11
The categories of this paper are: hep-lat
29
The categories of this paper are: funct-an
21
The categories of this paper are: adap-org
19
The categories of this paper are: eess
36
The categories of this paper are: cmp-lg
0
The categories of this paper are: hep-ph
30
The categories of this paper are: q-alg
10
The categories of this paper are: q-bio
3
The categories of this paper are: physics
17
The categories of this paper are: q-fin
9
The categories of this paper are: nlin