Plasma heating by Alfven wave filamentation: A relevant mechanism in the solar corona and the interstellar medium

A mechanism for small-scale generation in magnetically dominated, homogeneous space plasmas is proposed, resulting from transverse collapse (filamentation) of weakly nonlinear, circularly polarized Alfven waves. It is argued that waves whose frequencies exceed a magnitude of about 10 Hz can significantly contribute to the heating of open coronal holes and to the acceleration of the fast solar wind. In coronal loops, this frequency lower bound reduces to 1 Hz. The importance of Alfven wave filamentation is also demonstrated in the warm ionized phase of the interstellar medium.