The paper gives a symplectic-geometric account of semiclassical Gaussian wave packet dynamics. We employ geometric techniques to “strip away” the symplectic structure behind the time-dependent Schrödinger equation and incorporate it into semiclassical wave packet dynamics. We show that the Gaussian wave packet dynamics of Heller is a Hamiltonian system with respect to the symplectic structure, ...

We study numerically the dynamics of a scroll wave in a three-dimensional (3D) excitable medium in the presence of substantial meandering of the corresponding 2D spiral wave in the Aliev-Panfilov model. We identify three types of dynamics of the scroll wave filament--quasi-2D, periodic, and aperiodic meandering--and we study their dependence on parameter settings and thickness of the medium.

Plunging wave breaking is of great importance to ship hydrodynamics, including strong turbulence with large amounts of air entrainment, bubbles, droplets, jets, and spray. Previous experimental fluid dynamics (EFD) and computational fluid dynamics (CFD) studies on plunging wave breaking are mainly focused on the global structures of the wave breaking, such as wave elevation, jet, air cavity, an...

The dynamics of quantum systems are encoded in the amplitude and phase of wave packets. However, the rapidity of electron dynamics on the attosecond scale has precluded the complete characterization of electron wave packets in the time domain. Using spectrally resolved electron interferometry, we were able to measure the amplitude and phase of a photoelectron wave packet created through a Fano ...

The de Broglie-Bohm formulation of the Schrodinger equation implies conservation of the wave function probability density associated with each quantum trajectory in closed systems. This conservation property greatly simplifies numerical implementations of the quantum trajectory dynamics and increases its accuracy. The reconstruction of a wave function, however, becomes expensive or inaccurate a...

Wave packet dynamics has exposed interesting new phenomena in several fields. In femto-chemistry [1,2] we are now able to time-resolve chemical processes and also observe effects such as the breakup and revival of wave packets [3]. In atom optics wave packets are used to model matter waves [4] and electron wave packets are seen in the dynamics of Rydberg atoms [5]. The numerical modelling of wa...

A remarkable phenomenon in turbulent flows is the spontaneous emergence of coherent large spatial scale zonal jets. Geophysical examples of this phenomenon include the Jovian banded winds and the Earth’s polar front jet. In this work a comprehensive theory for the interaction of jets with turbulence, Stochastic Structural Stability Theory, is applied to the problem of understanding the formatio...

Although spiral waves are ubiquitous features of nature and have been observed in many biological systems, their existence and potential function in mammalian cerebral cortex remain uncertain. Using voltage-sensitive dye imaging, we found that spiral waves occur frequently in the neocortex in vivo, both during pharmacologically induced oscillations and during sleep-like states. While their life...

Cross-shore sediment transport is one of the effective factors in erosion and sedimentation, and affects dynamics of the beach profile in coastal areas. Furthermore, sandbar migration due to cross-shore sediment transport mostly effects beach nourishment, displacement of pollutions trapped in sediments, and organism and plants’ lives.  In this manuscript, sandbar migration due to cro...

Shock-wave formation is a generic scenario of wave dynamics known in nonlinear acoustics, fluid dynamics, astrophysics, seismology, and detonation physics. Here, we show that, in nonlinear optics, remarkably short, attosecond shock transients can be generated through a strongly coupled spatial and temporal dynamics of ultrashort light pulses, suggesting a pulse self-compression scenario whereby...