Elastic waves in helical waveguides

Elastic waves in helical waveguides

Nonlinear waves and wave scattering in layered elastic waveguides

A Remark on Helical Waveguides

Motivated by a proposal to create an optical helix-shaped waveguides for cold atoms and molecules, we discuss local perturbations which can create bound states in such a setting. This is known about a local slowdown of the twist; we show that a similar effect can result from a local tube protrusion or a change of the helix radius in correlation with its pitch angle.

Numerical interaction of boundary waves with perfectly matched layers in elastic waveguides

Perfectly matched layers (PML) are a novel technique to simulate the absorption of waves in open domains. Wave propagation in isotropic elastic waveguides has the possibility to support propagating modes with negative group velocities and long wavelengths. Propagating modes with negative group velocities can lead to temporally growing solutions in the PML. In this paper, we demonstrate that neg...

Cosmological Waveguides for Gravitational Waves

We study the linearized equations describing the propagation of gravitational waves through dust. In the leading order of the WKB approximation, dust behaves as a nondispersive, non-dissipative medium. Taking advantage of these features, we explore the possibility that a gravitational wave from a distant source gets trapped by the gravitational field of a long filament of galaxies of the kind s...