Related papers: Thin Layer Approximation in 3-D
Observations at long wavelengths, in the wide interval from a few to 1000 micron, are essential to study diffuse media in galaxies, including all kinds of atomic, ionic and molecular gases and dust grains. Hence they are particularly suited…
We present the first 3-dimensional simulations following the evolution of supernova shocks from their inception in the stellar core through the development of a supernova remnant into the Sedov phase. Our set of simulations use two…
Polarization has been detected at early times for all types of supernova, indicating that such systems result from or quickly develop some form of asymmetry. In addition, the detection of strong line polarization in supernovae is suggestive…
High surface density, rapidly star-forming galaxies are observed to have $\approx 50-100\,{\rm km\,s^{-1}}$ line-of-sight velocity dispersions, which are much higher than expected from supernova driving alone, but may arise from large-scale…
The physical processes involved in diffusion of Galactic cosmic rays in the interstellar medium are addressed. We study the possibility that the nonlinear MHD cascade sets the power-law spectrum of turbulence which scatters charged…
Galaxies comprise intricate networks of interdependent processes which together govern their evolution. Central among these are the multiplicity of feedback channels, which remain incompletely understood. One outstanding problem is the…
Simulations of three dimensional ultrasound propagation in heterogeneous media are computationally intensive due to the constraints arising from the large size of the domain, which is on the order of hundreds of wavelengths, and the small…
We study the propagation of tension caused by an external force along a long polymeric molecule in two different settings, namely along a free polymer in 3d space being pulled from one end, and along a pre-stretched circular polymer,…
An approximation is elaborated for the paraxial propagation of diffracted beams, with both one- and two-dimensional cross sections, which are released from apertures with sharp boundaries. The approximation applies to any beam under the…
We experimentally probe nonlinear wave propagation in weakly compressed granular media, and observe a crossover from quasi-linear sound waves at low impact, to shock waves at high impact. We show that this crossover grows with the confining…
We present the first complete 3-dimensional simulations of the core-collapse of a massive star from the onset of collapse to the resultant supernova explosion. We compare the structure of the convective instabilities that occur in…
A recently developed method has been extended to a nonlocal equation arising in steady water wave propagation in two dimensions. We obtain analyic approximation of steady water wave solution in two dimensions with rigorous error bounds for…
The dispersion characteristics of an circularly polarized electromagnetic wave of arbitrary amplitude, propagating in a highly (thermally and kinematically) relativistic plasma, are shown to approach those of a linear wave in an…
Simulations of structure formation in the Universe predict accretion shock waves at the boundaries of the large-scale structures as sheets, filaments, and clusters of galaxies. If magnetic fields are present at these shocks, particle…
Multiwavelength observations of Type II supernovae have shown evidence for the interaction of supernovae with the dense slow winds from the red supergiant progenitor stars. Observations of planetary nebulae and the nebula around SN 1987A…
The nonlinear propagation of intense incoherent photons in a photon gas is considered. The photon-photon interactions are governed by a pair of equations comprising a wave-kinetic equation for the incoherent photons in the presence of the…
To study large-scale structure in the Universe a full census of the contents are required. This is even more important when the processes of galaxy formation are being investigated. In the last year the population of distant galaxies that…
We consider semilinear hyperbolic systems with a trilinear nonlinearity. Both the differential equation and the initial data contain the inverse of a small parameter $\varepsilon$, and typical solutions oscillate with frequency proportional…
In this paper we set forth new exact analytical Superluminal localized solutions to the wave equation for arbitrary frequencies and adjustable bandwidth. The formulation presented here is rather simple, and its results can be expressed in…
Supersonic turbulence fragments the interstellar medium into dense sheets, filaments, cores and large low density voids. The turbulence is driven on large scales, probably predominantly by supernovae. The scaling properties of supersonic…