Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Dynamic light scattering measurements in the activated regime of dense
  colloidal hard spheres   We use dynamic light scattering and numerical simulations to study the
approach to equilibrium and the equilibrium dynamics of systems of colloidal
hard spheres over a broad range of density, from dilute systems up to very
concentrated suspensions undergoing glassy dynamics. We discuss several
experimental issues (sedimentation, thermal control, non-equilibrium aging
effects, dynamic heterogeneity) arising when very large relaxation times are
measured. When analyzed over more than seven decades in time, we find that the
equilibrium relaxation time, tau_alpha, of our system is described by the
algebraic divergence predicted by mode-coupling theory over a window of about
three decades. At higher density, tau_alpha increases exponentially with
distance to a critical volume fraction phi_0 which is much larger than the
mode-coupling singularity. This is reminiscent of the behavior of molecular
glass-formers in the activated regime. We compare these results to previous
work, carefully discussing crystallization and size polydispersity effects. Our
results suggest the absence of a genuine algebraic divergence of tau_alpha in
colloidal hard spheres.

2
The categories of this paper are: math
29
The categories of this paper are: funct-an
27
The categories of this paper are: comp-gas
13
The categories of this paper are: quant-ph
5
The categories of this paper are: gr-qc
37
The categories of this paper are: supr-con
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
31
The categories of this paper are: ao-sci
11
The categories of this paper are: hep-lat
30
The categories of this paper are: q-alg
12
The categories of this paper are: nucl-th
24
The categories of this paper are: dg-ga
6
The categories of this paper are: astro-ph
16
The categories of this paper are: stat