Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Discontinuous evolution of the structure of stretching polycrystalline
  graphene   Polycrystalline graphene has an inherent tendency to buckle, i.e. develop
out-of-plane, three-dimensional structure. A force applied to stretch a piece
of polycrystalline graphene influences the out-of-plane structure. Even if the
graphene is well-relaxed, this happens in non-linear fashion: occasionally, a
tiny increase in stretching force induces a significant displacement, in close
analogy to avalanches, which in turn can create vibrations in the surrounding
medium. We establish this effect in computer simulations: by continuously
changing the strain, we follow the displacements of the carbon atoms that turn
out to exhibit a discontinuous evolution. Furthermore, the displacements
exhibit a hysteretic behavior upon the change from low to high stress and back.
These behaviors open up a new direction in studying dynamical elasticity of
polycrystalline quasi-two-dimensional systems, and in particular the
implications on their mechanical and thermal properties.

25
The categories of this paper are: patt-sol
30
The categories of this paper are: q-alg
14
The categories of this paper are: math-ph
28
The categories of this paper are: alg-geom
27
The categories of this paper are: comp-gas
5
The categories of this paper are: gr-qc
10
The categories of this paper are: q-bio
19
The categories of this paper are: eess
1
The categories of this paper are: cs
13
The categories of this paper are: quant-ph
15
The categories of this paper are: nucl-ex
26
The categories of this paper are: bayes-an
11
The categories of this paper are: hep-lat
33
The categories of this paper are: plasm-ph
17
The categories of this paper are: q-fin
16
The categories of this paper are: stat