This special issue of Journal of Physics: Condensed Matter collects together a series of contributions first reported at the
workshop `Structural Arrest Transitions in Colloidal Systems With Short-Range Attractions'
which was held in Messina (Italy) on 17-20 December 2003. The aim of the workshop was to discuss, in
depth, the recent progress on both the mode coupling theory predictions and their experimental tests on
various aspects of structural arrest transitions in colloidal systems with short-range attractions. Indeed,
the last five years had seen an incredible progress in the understanding of the slow dynamics in colloidal
suspensions and of the formation of disordered arrested states in these systems, both at low and at high
packing fraction. The time was ripe for an open discussion, not only of the previous achievements, but
also of foreseeable future developments.
Browsing through this issue, the reader will immediately notice the presence of words and ideas
indicating a flowering of the original novel idea of the structural arrest transition in densely packed
systems. The dynamical arrest phenomena close to the colloidal glass transition is discussed together
with several other types of dynamic arrest, in particular the ones also able to generate arrested states at
extremely low packing fractions. In this issue, studies of glass and gel formation are often found
together. Novel and/or deeper connections between dynamical arrest and cluster formation, both in
equilibrium and out of equilibrium conditions were presented and discussed during the workshop and
reported in the accompanying articles. The theoretical frontier is pushed toward systems where short-range
attractions are complemented by long-range repulsions, favouring the description of supramolecular
ordering in protein solutions, in the same theoretical framework developed for charged colloidal
systems. Mode-coupling theory calculations, strengthened by the notable agreement between theoretical
predictions and experimental results, are tackling more sophisticated dynamical phenomena, the
dynamics close to higher-order singularity points which are expected to exist in these types of systems.
The seventeen articles included in this issue provide a state-of-the-art description of the experimental,
theoretical and numerical studies reported at the workshop.
We believe these articles will be of interest not only to scientist interested in colloidal sciences, but also
to the wider community of researchers interested in basic dynamical properties of soft and bio-matter, of
the liquid state and of disordered systems in general.
We are grateful to the Bonino-Pulejo Foundation (Messina, Italy) for the patronage and enthusiatic
support during the workshop. Our thanks also go to the Messina University, the Department of Energy
(USA), the MIUR-PRIN-02 UCJTCS (Italy), the European Community Marie-Curie Project
MRTN-CT-2003-504712 and the Bonino-Pulejo Foundation which contributed financial support to the Congress.