I propose we make the tag non-linear-dynamics a synonym of complex-systems.
Currently, non-linear-dynamics is set as a synonym of non-linear-systems, but I'd like to argue that the most common usage of the term nonlinear dynamics is in the sense of being the (nonlinear) dynamics of dynamical-systems and it should, just as the latter, be considered a synonym of complex-systems:
The common understanding of the subject, as described, e.g., by the the journal Nature, is:
Nonlinear dynamics is the branch of physics that studies systems governed by equations more complex than the linear, aX+b form. Nonlinear systems, such as the weather or neurons, often appear chaotic, unpredictable or counterintuitive, and yet their behaviour is not random.
which isn't expressed by the current description of the nonlinear systems tag:
The term non-linear or nonlinear has several definitions but is generally used to describe a system that cannot be approximated by a superposition principle or perturbative approach.
The Wikipedia entry for Complex Systems lists "Nonlinear dynamics" among its topics.
Research institutions around the world clearly consider nonlinear dynamics as a subject in the context of complex systems. For instance (research group name, followed by keywords):
- Manchester Centre for Nonlinear Dynamics
granular media, fluid dynamics, turbulence, chaos - Center for Nonlinear Dynamics (UT - Austin)
fluid dynamics, granular matter, social dynamics - Institute for Nonlinear Dynamics (Göttingen)
pattern formation, fluid dynamics, neurophysics, networks - Nonlinear Dynamics, Chaos and Complex Systems (U. Maryland)
chaos, granular dynamics, pattern formation, networks - Nonlinear Dynamics (U. Bayreuth)
complex fluids, soft matter, geoecology, chaos - Nonlinear Dynamics Group (U. Kyoto)
statistical physics, structure formation, patterns, neuronal systems - Nonlinear Physics Group (Tokyo M. U.)
chaos, Hamiltonian systems, quantum chaos - Nonlinear and Complex Systems Laboratory at POSTECH (Korea)
pattern formation, self-organization, chaos, brain science - Oscillations Control Group (U. of São Paulo)
turbulence, chaos, complex systems, networks
- Manchester Centre for Nonlinear Dynamics
