Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Fluctuating particle motion during shear induced granular compaction   Using a refractive index matching method, we investigate the trajectories of
particles in a three dimensional granular packing submitted to cyclic shear
deformation. The particle motion observed during compaction is not diffusive
but exhibits transient cage effect, similar to the one observed in colloidal
glasses. We precisely study the statistics of the step size between two
successive cycles and observe that it is proportional to the shear amplitude.
The link between the microscopic observations and the macroscopic evolution of
the volume fraction during compaction is discussed.

18
The categories of this paper are: econ
16
The categories of this paper are: stat
22
The categories of this paper are: chao-dyn
27
The categories of this paper are: comp-gas
33
The categories of this paper are: plasm-ph
32
The categories of this paper are: atom-ph
20
The categories of this paper are: acc-phys
36
The categories of this paper are: cmp-lg
37
The categories of this paper are: supr-con
12
The categories of this paper are: nucl-th
24
The categories of this paper are: dg-ga
23
The categories of this paper are: solv-int
9
The categories of this paper are: nlin
17
The categories of this paper are: q-fin
2
The categories of this paper are: math
30
The categories of this paper are: q-alg