Waves and turbulence are two fundamental characteristics of space plasmas. In this context, it seems natural to rely on wave turbulence theory to interpret in situ data, such as that provided by PSP/MMS (NASA), whose degree of precision is unique in astrophysics. In this seminar, I will review recent observations and theoretical results on MHD wave turbulence, then focus on the case of compressible MHD in the limit of low beta, for which we can prove that the Iroshnikov-Kraichnan spectrum is an exact solution.

References:

S. Galtier, Fast magneto-acoustic wave turbulence and the Iroshnikov-Kraichnan spectrum, J. Plasma Physics 89 (2023)

S. Galtier, Physics of wave turbulence, Cambridge University Press (2022)