Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Dynamical collective memory in fluidized granular materials   Recent experiments with rotational diffusion of a probe in a vibrated
granular media revealed a rich scenario, ranging from the dilute gas to the
dense liquid with cage effects and an unexpected superdiffusive behavior at
large times. Here we setup a simulation that reproduces quantitatively the
experimental observations and allows us to investigate the properties of the
host granular medium, a task not feasible in the experiment. We discover a
persistent collective rotational mode which emerges at high density and low
granular temperature: a macroscopic fraction of the medium slowly rotates,
randomly switching direction after very long times. Such a rotational mode of
the host medium is the origin of probe's superdiffusion. Collective motion is
accompanied by a kind of dynamical heterogeneity at intermediate times (in the
cage stage) followed by a strong reduction of fluctuations at late times, when
superdiffusion sets in.

1
The categories of this paper are: cs
29
The categories of this paper are: funct-an
14
The categories of this paper are: math-ph
31
The categories of this paper are: ao-sci
20
The categories of this paper are: acc-phys
10
The categories of this paper are: q-bio
35
The categories of this paper are: mtrl-th
5
The categories of this paper are: gr-qc
36
The categories of this paper are: cmp-lg
16
The categories of this paper are: stat
23
The categories of this paper are: solv-int
3
The categories of this paper are: physics
22
The categories of this paper are: chao-dyn
24
The categories of this paper are: dg-ga
17
The categories of this paper are: q-fin
34
The categories of this paper are: chem-ph