Abstract: I will present two new results about macroscopic behavior of chains of harmonic oscillators.
1) The strain, momentum and energy of a chain of harmonic oscillators with random masses, even out of thermal equilibrium, converge to the solution of the Euler equation under hyperbolic space time scaling (in collaboration with Francois Huveneers and Cedric Bernardin).
2) Macroscopic scattering (in a hyperbolic scaling) caused by a Langevin thermostat in contact with a point of the harmonic chain (in collaboration with Tomasz Komorowski, Lenya Ryzhik and Herbert Spohn).