Emergence dans les modèles de calcul – EMC

Computational models are inherently linked to the concept of complex systems: in many complex systems the computational aspects play a crucial role in terms of predictability/unpredictability and also in the analysis of chaos appearance. Conversely, complex behaviours are observed in computational models' evolution in many different ways: some single instance of a model having a complex behaviour or a whole regular class of instances showing a complex inherent structure. We focus on a formal study of these notions with the help of different tools ' mainly from theoretical computer science. This point of view can be reformulated as the study of intrinsic properties of complex systems in the framework of theoretical computer science. The formal models we consider cover a wide range: from Turing machines modelling pure computation aspects, to Tilings modelling geometrical aspects, through Cellular Automata modelling combinations of geometric and computational features. There is a need to model emergence in our contexts: the notion itself comes from symptomatic resemblance in different systems. The analogy is often difficult to describe and even more difficult to analyse. Thereby, our main goal can be seen as a twofold program: the study of, on one hand, the computational aspects of emergence; on the other hand, the dynamics of emerging properties.