Normal and Anomalous Diffusion in Soft Lorentz Gases

Engineered nanoscale structures known as artificial graphene exhibit the properties of real graphene but in a setup where it is easy to tune features such as the electronic density, lattice constant, geometry or coupling with the environment. Read more

On reversals in 2D turbulent Rayleigh-Bénard convection: Insights from embedding theory and comparison with proper orthogonal decomposition analysis

In the 1980s, most researchers approached empirical analysis of low-dimensional dynamical systems through the famous Takens embedding theorem, which guarantees that the attractor of any dynamical system can be reconstructed from samples of the values of key variables. Read more

The hammam effect or how a warm ocean enhances large scale atmospheric predictability

Will climate change make weather forecasting harder than it currently is? Or, could a warmer planet make prediction easier? The answer isn’t obvious. Because atmospheric dynamics are chaotic, there are practical limits to predictability, regardless of data precision and available computing power. Read more

Common Trajectories for Urban Economies

Large cities play a disproportionate role in global economic productivity and innovation. Their productivity advantage rests on specialization and the concentration of many diverse skills and capabilities in one place, multiplying economic opportunities and efficiencies. Even so, cities do not appear to develop along one predictable trajectory. Read more

Conditioned Lyapunov exponents for random dynamical systems

Lyapunov exponents play a central role in dynamical systems theory, and offer a measure of the local instability that lies behind deterministic chaos and the sensitive dependence of trajectories on initial conditions. Read more

A test on methods for complete magnitude estimation based on earthquake catalogues

Earthquake statistics follow an approximate scaling law – the famous Gutenberg-Richter law – which states that the number of earthquakes having magnitude m larger than some value M falls off as a power law with an exponent b. The value of b can be estimated from recorded data in earthquake catalogues. Read more

Spectra of Sparse Non-Hermitian Random Matrices

Random matrix theory starts from the assumption that the large-scale behaviour of a complex system should be governed by its symmetries and the statistical properties of its parameters, and be relatively insensitive to the precise details of each interacting element. Read more

Transport fluctuations in integrable models out of equilibrium

The physics of many-body systems out of equilibrium poses some of the most challenging questions in modern science. Particularly novel behaviour occurs in one dimension, where integrability often strongly affects the non-equilibrium physics, and numerous conservation laws constrain the natural relaxation to stationary states. Read more

Synchronization of Chaos

The Dutch scientist Christiaan Huygens famously observed in 1665 that two pendulum-clocks situated in the same room would, over time, come to be synchronized. The explanation? The two clocks were actually interacting very weakly through movements of the floor. Read more

Attractor dimension of time-averaged climate observables: insights from a low-order ocean-atmosphere model

The climate system involves a complex interplay between the ocean and atmosphere. Studies of this interplay typically rely on model simulations in comparison with time series data for some feature of oceanic and/or atmospheric circulation on a regional or larger scale. Read more