Nonlinear growth of firehose and mirror fluctuations in astrophysical plasmas.
In turbulent high-beta astrophysical plasmas (exemplified by the galaxy cluster plasmas), pressure-anisotropy-driven firehose and mirror fluctuations grow nonlinearly to large amplitudes, deltaB/B approximately 1, on a time scale comparable to the turnover time of the turbulent motions. The principle of their nonlinear evolution is to generate secularly growing small-scale magnetic fluctuations that on average cancel the temporal change in the large-scale magnetic field responsible for the pressure anisotropies. The presence of small-scale magnetic fluctuations may dramatically affect the transport properties and, thereby, the large-scale dynamics of the high-beta astrophysical plasmas.
Schekochihin
A A
AA
Plasma Physics, Blackett Laboratory, Imperial College, London SW7 2AZ, United Kingdom. a.schekochihin@imperial.ac.uk
Cowley
S C
SC
Kulsrud
R M
RM
Rosin
M S
MS
Heinemann
T
T