This work examines the extent to which a few basic concepts that apply to plane waves, for example, the refraction of waves up the gradient of the index of refraction, apply to stratospheric planetary waves. This is done by studying the relation between group velocity (Cg) and the wave activity velocity, which is defined as the Eliassen–Palm flux divided by the wave activity density (Va 5 F/A)....

In this work we briefly review the wave packet approach of two generation neutrino oscillation, aiming its description in a progenitor star supernova environment. We begin calculating the wave packet size in many situations: solar and supernova plasma medium, considering nuclear interactions, as well as accelerators and reactors. This quantity is important to calculate the coherence length, whi...

We use wave packet mode quantization to compute the creation of massless scalar quantum particles in a colliding plane wave spacetime. The background spacetime represents the collision of two gravitational shock waves followed by trailing gravitational radiation which focus into a Killing-Cauchy horizon. The use of wave packet modes simplifies the problem of mode propagation through the differe...

We produce oriented rotational wave packets in CO and measure their characteristics via high harmonic generation. The wave packet is created using an intense, femtosecond laser pulse and its second harmonic. A delayed 800 nm pulse probes the wave packet, generating even-order high harmonics that arise from the broken symmetry induced by the orientation dynamics. The even-order harmonic radiatio...

This Letter reports experimental results on random temporal dark solitons. One excites an incoherent large-amplitude propagating spin-wave packet in a ferromagnetic film strip with a repulsive, instantaneous nonlinearity. One then observes the random formation of dark solitons from this wave packet. The solitons appear randomly in time and in position relative to the entire wave packet. They ca...

This paper introduces the synchrosqueezed wave packet transform as a method for analyzing twodimensional images. This transform is a combination of wave packet transforms of a certain geometric scaling, a reallocation technique for sharpening phase space representations, and clustering algorithms for modal decomposition. For a function that is a superposition of several wave-like components wit...

Expressions governing coherence scales of sound passing through a moving packet of nonlinear internal waves in a continental shelf environment are presented. The expressions describe the temporal coherence scale at a point, and the horizontal coherence scale in a plane transverse to the acoustic path, respectively. Factors in the expressions are the wave packet propagation speed, wave packet pr...

We consider the high-frequency Helmholtz equation with a given source term, and a small absorption parameter α > 0. The high-frequency (or: