MPE StudioMath of Planet Earth
Dynamical Toolkit · 14

Wave Mode Analysis

Eigenvalues, dispersion, and propagation

Wave-mode analysis diagonalizes coupled linear PDEs into independent patterns with their own propagation speeds.

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The essential idea: the eigenvalues of the coefficient matrix determine the allowed wave speeds.

Watch the concept

One Concept · One Example

VIDEO COMPANION

Wave Mode Analysis

Presented by Charlotte Moser · Coming soon

What to notice

The idea in 30 seconds

The mathematical structure

Coupled system

Two fields exchange spatial derivatives.

uₜ+cvₓ=0, vₜ+cuₓ=0

Decoupled modes

A change of variables reveals two transport equations.

(w+)ₜ+c(w+)ₓ=0, (w−)ₜ−c(w−)ₓ=0
Explore

Split one disturbance into two wave modes

Follow right- and left-traveling packets, then reconstruct the physical variables u and v.

x=-6x=6
w+ rightw− leftu=(w++w−)/2v=(w+−w−)/2
KEY TAKEAWAY

Diagonalization reveals independent wave modes hidden inside coupled equations.