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Nonlinear phenomena are phenomena, which, in contrast to a linear system, cannot be explained by a mathematical relationship of proportionality (that is, a linear relationship between two variables). For example, the spread of an infectious disease is most often exponential, rather than linear, with time.
Spiral waves of cell density can form and propagate through bacterial biofilms. These waves are formed by a self-organization process that coordinates pulling forces between neighbouring cells.
Intermittency is the behavior of extreme fluctuations observed in the flow of a fluid that is often associated with high Reynolds numbers. Here, the authors report intermittency in elastic turbulence at the low Reynolds number and high Deborah number limit.
Spiral waves of cell density can form and propagate through bacterial biofilms. These waves are formed by a self-organization process that coordinates pulling forces between neighbouring cells.
Stable regions in four-dimensional phase space have been observed by following the motion of accelerated proton beams subject to nonlinear forces. This provides insights into the physics of dynamical systems and may lead to improved accelerator designs.
Ageing is a non-linear, irreversible process that defines many properties of glassy materials. Now, it is shown that the so-called material-time formalism can describe ageing in terms of equilibrium-like properties.
Predicting the large-scale behaviour of complex systems is challenging because of their underlying nonlinear dynamics. Theoretical evidence now verifies that many complex systems can be simplified and still provide an insightful description of the phenomena of interest.