Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: How to "measure" a structural relaxation time that is too long to be
  measured?   It has recently become possible to prepare ultrastable glassy materials
characterised by structural relaxation times which vastly exceed the duration
of any feasible experiment. Similarly, new algorithms have led to the
production of ultrastable computer glasses. Is it possible to obtain a reliable
estimate of a structural relaxation time that is too long to be measured? We
review, organise, and critically discuss various methods to estimate very long
relaxation times. We also perform computer simulations of three dimensional
ultrastable hard spheres glasses to test and quantitatively compare some of
these methods for a single model system. The various estimation methods
disagree significantly and it is not yet clear how to accurately estimate
extremely long relaxation times.

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The categories of this paper are: eess
13
The categories of this paper are: quant-ph
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The categories of this paper are: dg-ga
20
The categories of this paper are: acc-phys
2
The categories of this paper are: math
28
The categories of this paper are: alg-geom
26
The categories of this paper are: bayes-an
30
The categories of this paper are: q-alg
6
The categories of this paper are: astro-ph
21
The categories of this paper are: adap-org
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The categories of this paper are: nucl-ex
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The categories of this paper are: patt-sol
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The categories of this paper are: stat
8
The categories of this paper are: hep-ex
22
The categories of this paper are: chao-dyn
0
The categories of this paper are: hep-ph