Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Emergent spatial structures in critical sandpiles   We introduce and study a new directed sandpile model with threshold dynamics
and stochastic toppling rules. We show that particle conservation law and the
directed percolation-like local evolution of avalanches lead to the formation
of a spatial structure in the steady state, with the density developing a power
law tail away from the top. We determine the scaling exponents characterizing
the avalanche distributions in terms of the critical exponents of directed
percolation in all dimensions.

33
The categories of this paper are: plasm-ph
0
The categories of this paper are: hep-ph
36
The categories of this paper are: cmp-lg
26
The categories of this paper are: bayes-an
12
The categories of this paper are: nucl-th
14
The categories of this paper are: math-ph
8
The categories of this paper are: hep-ex
5
The categories of this paper are: gr-qc
31
The categories of this paper are: ao-sci
11
The categories of this paper are: hep-lat
25
The categories of this paper are: patt-sol
3
The categories of this paper are: physics
10
The categories of this paper are: q-bio
21
The categories of this paper are: adap-org
22
The categories of this paper are: chao-dyn
6
The categories of this paper are: astro-ph