Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Influence of Ortho-H2 Clusters on the Mechanical Properties of Solid
  Para-H2   The quantum diffusion of ortho-H2 impurities in solid para-H2 has been
investigated with a torsional oscillator technique. The unclustering dynamics
of agglomerated impurities with increasing temperature are found to greatly
affect the resonant period of oscillation. Based on the observed trends in both
experimental data and complementary finite element calculations, we find that
the oscillation period predominantly reflects changes in the solid's elastic
response to the minute inertial stresses imposed on it. It is likely that the
small but abrupt increase in the resonant period observed above 100 mK in high
purity H2 samples is due to the interplay between remnant ortho-H2 impurities
and dislocations, and not a signature of a supersolid to normal solid
transition.

2
The categories of this paper are: math
13
The categories of this paper are: quant-ph
30
The categories of this paper are: q-alg
11
The categories of this paper are: hep-lat
36
The categories of this paper are: cmp-lg
5
The categories of this paper are: gr-qc
17
The categories of this paper are: q-fin
14
The categories of this paper are: math-ph
16
The categories of this paper are: stat
7
The categories of this paper are: hep-th
8
The categories of this paper are: hep-ex
34
The categories of this paper are: chem-ph
20
The categories of this paper are: acc-phys
28
The categories of this paper are: alg-geom
6
The categories of this paper are: astro-ph
15
The categories of this paper are: nucl-ex