Foreword

We started thinking about a dossier on coarsening because, although many excellent reviews exist, a collection of papers where the diverse manifestations of this phenomenon were gathered together and discussed at a relatively broad and basic level, addressing both theory and experiments, would have been useful. Coarsening certainly plays an important role in physical sciences, where phenomena of phase ordering and phase sepa- ration are widespread [1–3]. But it is also relevant in biology, characterizing for instance the motion of birds flocks [4] or bacterial suspensions [5]; in social sciences, with several implications in finance and opinion making [6]; in chemistry [7], being a possible outcome of sustained reactions. Coarsening is also important for a wealth of applications in metallurgical and plastic productions, food [8] and drug preparations, construction industry and many other areas. The pattern formation observed in driven systems [9] is also very often the outcome of a coarsening process, although many other dynamical features such as traveling waves and chaos, non-equilibrium stationary and oscillating states may be observed. In particular, coarsening has been recognized to be widespread in surface science where Ostwald ripen- ing [10]—a phenomenon at the historical roots of coarsening studies—is observed.