Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Correlations and critical behavior of the q-model   The q-model is a random walk model used to describe the flow of stress in a
stationary granular medium. Here we derive the exact horizontal and vertical
correlation functions for the q-model in two dimensions. We show that close to
a critical point identified in earlier work these correlation functions have a
universal scaling form reminiscent of thermodynamic critical phenomena. We
determine the form of the universal scaling function and the associated
critical exponents $\nu$ and $z$.

29
The categories of this paper are: funct-an
21
The categories of this paper are: adap-org
32
The categories of this paper are: atom-ph
19
The categories of this paper are: eess
25
The categories of this paper are: patt-sol
33
The categories of this paper are: plasm-ph
0
The categories of this paper are: hep-ph
27
The categories of this paper are: comp-gas
22
The categories of this paper are: chao-dyn
16
The categories of this paper are: stat
15
The categories of this paper are: nucl-ex
28
The categories of this paper are: alg-geom
18
The categories of this paper are: econ
24
The categories of this paper are: dg-ga
30
The categories of this paper are: q-alg
31
The categories of this paper are: ao-sci