Joseph Keir (Oxford): Nonlinear wave equations and the weak null condition

Donnerstag, 21. November 2019 14:00

Ort: Seminarraum 218, Währinger Str. 17, 2. Stock

The vacuum Einstein equations, written in "harmonic" or "wave coordinates", are a system of nonlinear wave equations. Interestingly, very similar equations exhibit finite‐time blowup, while the Einstein equations themselves admit global solutions for small initial data. The extra structure which enables them to avoid blowup is called the "weak null structure". In this talk I will explore this structure, giving a general definition and then some subclasses for which we can prove global existence for small initial data.
I will also give some details of the proof of global existence for solutions to these classes of equations.

Location:

Raum 218, Währinger Str. 17, 2. Stock