NOTES ON PHYSICS GROUP AND WAVE VELOCITY

On the group-velocity property for wave- activity conservation laws

The density and the flux of wave-activity conservation laws are generally required to satisfy the group-velocity property: under the WKB approximation (i.e., for nearly monochromatic small-amplitude waves in a slowly varying medium), the flux divided by the density equals the group velocity. It is shown that this property is automatically satisfied if, under the WKB approximation, the only sour...

Lecture notes : Group theory and its applications in physics

Notes on Wave Equations

2.1.1 Full Maxwell’s Equations The full set of Maxwell’s equations come in two forms. The first form is called either the integral or volume form and is shown in Table 2.1. These set of four equations show the interrelationships of the basic physical quantities studied in electromagnetics, which are summarized in Table 2.2. This form of Maxwell’s equations elegantly relates volumeand area-integ...

Notes on Motion Estimation 1 3d Velocity and Image Velocity

There are a great variety of applications that depend on analyzing the motion in image sequences. These include motion detection for surveillance, image sequence data compression (MPEG), image understanding (motion-based segmentation, depth/structure from motion), obstacle avoidance, image registration and compositing. The rst step in processing image sequences is typically image velocity estim...

Notes on Group Theory