---

If we are given an electromagnetic medium tensor we can compute the speed of a propagating signal. For example, in a homogeneous medium we can compute the phase velocity using plane waves. A less well understood question is the converse: If we know the behaviour of phase velocity in all possible directions for an unknown medium, how much can we say about the anisotropic structure of that medium? In this talk we describe a number of results on this question in the setting of linear, local, and non-dissipative (skewon-free) media. In particular, we discuss the classification of medium tensors where wave propagation is determined by one or two Lorentz null cones.

---

Matias Dahl, Aalto-yliopisto, Finland
Seminarraum Theoretische Physik
Contact: not specified