# Wave

This tag concerns posts about linear and nonlinear wave equations.

### The Nirenberg Trick and Wave Maps

The "Nirenberg trick" or "Nirenberg transformation" is the observation1 that the semilinear wave equation …

### Simulating Closed Cosmic Strings

One of my current research interests is in the geometry of constant-mean-curvature time-like submanifolds of Minkowski space. A special …

### Shooting particles with Python

Numpy simulation of how classical and quantum particles interact with potential barriers.

### Blow-up of QNLW with Small Initial Data à la Christodoulou

Lecture slides that Gustav Holzegel and I used for the January 13-14, 2014 OXPDE Workshop at Oxford University.

### A Cute Little Wave Estimate

Let us consider first the linear wave equation $\Box u = 0$ on (1+d)-dimensional Minkowski space. A well known property of the wave …