The analysis of nonlinear wave equations has experienced a dramatic growth in the last ten years or so. The key factor in this has been the transition from linear analysis, first to the study of bilinear and multilinear wave interactions, useful in the analysis of semilinear equations, and next to the study of nonlinear wave interactions, arising in fully nonlinear equations. The dispersion phe...

We study the spatiotemporal structure of the biphoton entangled state generated by the four-wave mixing (FWM) process in a cold two-level atomic ensemble. We analyze, for the first time, the X-like shaped structure of the biphoton entangled state and the geometry of the biphoton correlation for different lengths and densities of the cold atomic ensemble. The propagation equations of the photon ...

New emerging multimedia standards, like the MPEG-4 standard allow the creation of virtual or synthetic acoustical environments. To auralize an environment from its geometric description, simulation algorithms for acoustic wave propagation are required. The different methods used for computational modeling of room acoustics can be divided into three groups [1]: statistical models, ray-based mode...

The effect of currents flowing across a bar field on resonant reflection of surface waves by the bars is investigated. Using a multiple-scale expansion, evolution equations for the amplitudes of linear waves are derived and used to investigate the reflection of periodic wave trains with steady amplitude for both normal and oblique incidence. The presence of a current is found to shift resonant ...

optical interferometry is being used as an efficient tool to analyse smooth surfaces for more than a century. although, due to introduction of novel computer assisted analyzing techniques and array detectors, like ccd, the speed and the precision of processing have been increased tremendously, but the main equation involved is not changed. the main equation is the intensity distribution in the ...

In 1932 Ettore Majorana proposed an infinite-component relativistic wave equation for particles of arbitrary integer and half-integer spin. In the late 80s and early 90s it was found that the higher-derivative geometric particle models underlie the Majorana equation, and that its (2+1)dimensional analogue provides with a natural basis for the description of relativistic anyons. We review these ...

Starting from a general form of the Zakharov equations the relations for electric fields and wave energy distributions at the very beginning of parametric instabilities are derived in dependence on initial Langmuir wave parameters. The corresponding dispersion equations in general and approximative forms are presented. These equations of the order up to eleven, with a different level of physica...