A zodiac of studies on complex systems

We offer a brief description of a set of interrelated research lines on the physics of complex systems developed under a unifying methodology grown out from nonlinear dynamics of low dimensionality. The research lines were, and are, developed over a two-decade period (tacitly or not) under a simplifying assumption (and a posteriori corroboration) of a drastic reduction of degrees of freedom. The studies are conveniently grouped into twelve units, and these in turn into four groups, as in a zodiac. The studies in the first group, named Sensitivities, Glasses and Localizations, have in common a clear-cut original opening in the sense that, to our knowledge, the main tenet or result is not found elsewhere. Those in the second group, named Sums, Rankings and Fluctuations, have as a starting point previous stimulating studies or ideas that we followed up but then we converted into separate approaches. The subjects in the third group, named Networks, Measures and Games, involve preset work programs to be followed but ended up within unanticipated, perhaps deeper, grounds. The topics in the final fourth group, named Partitions, Diagonals and Windows, occurred, or are taking place, as specific technical goals that have become after belated realizations to be possible contributions towards the answer of fundamental quests. We discuss connections underlying different aspects of these investigations. Nonlinear dynamics