Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Dynamics of a Rigid Rod in a Glassy Medium   We present simulations of the motion of a single rigid rod in a disordered
static 2d-array of disk-like obstacles. The rotational, $D_{\rm R}$, and
center-of-mass translational, $D_{\rm CM}$, diffusion constants are calculated
for a wide range of rod length $L$ and density of obstacles $\rho$. It is found
that $D_{\rm CM}$ follows the behavior predicted by kinetic theory for a hard
disk with an effective radius $R(L)$. A dynamic crossover is observed in
$D_{\rm R}$ for $L$ comparable to the typical distance between neighboring
obstacles $d_{\rm nn}$. Using arguments from kinetic theory and reptation, we
rationalize the scaling laws, dynamic exponents, and prefactors observed for
$D_{\rm R}$. In analogy with the enhanced translational diffusion observed in
deeply supercooled liquids, the Stokes-Einstein-Debye relation is violated for
$L > 0.6d_{\rm nn}$.

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The categories of this paper are: mtrl-th
1
The categories of this paper are: cs
18
The categories of this paper are: econ
6
The categories of this paper are: astro-ph
21
The categories of this paper are: adap-org
0
The categories of this paper are: hep-ph
22
The categories of this paper are: chao-dyn
8
The categories of this paper are: hep-ex
14
The categories of this paper are: math-ph
13
The categories of this paper are: quant-ph
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The categories of this paper are: comp-gas
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The categories of this paper are: funct-an
28
The categories of this paper are: alg-geom
11
The categories of this paper are: hep-lat
16
The categories of this paper are: stat
23
The categories of this paper are: solv-int