Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Collective rearrangement at the onset of flow of a polycrystalline
  hexagonal columnar phase   Creep experiments on polycrystalline surfactant hexagonal columnar phases
show a power law regime, followed by a drastic fluidization before reaching a
final stationary flow. The scaling of the fluidization time with the shear
modulus of the sample and stress applied suggests that the onset of flow
involves a bulk reorganization of the material. This is confirmed by X-ray
scattering under stress coupled to \textit{in situ} rheology experiments, which
show a collective reorientation of all crystallites at the onset of flow. The
analogy with the fracture of heterogeneous materials is discussed.

25
The categories of this paper are: patt-sol
30
The categories of this paper are: q-alg
31
The categories of this paper are: ao-sci
1
The categories of this paper are: cs
16
The categories of this paper are: stat
14
The categories of this paper are: math-ph
35
The categories of this paper are: mtrl-th
10
The categories of this paper are: q-bio
33
The categories of this paper are: plasm-ph
29
The categories of this paper are: funct-an
22
The categories of this paper are: chao-dyn
24
The categories of this paper are: dg-ga
20
The categories of this paper are: acc-phys
32
The categories of this paper are: atom-ph
28
The categories of this paper are: alg-geom
19
The categories of this paper are: eess