On the propagation of low-frequency fluctuations in the plasma sheet: 1. Cluster observations and magnetohydrodynamic analysis - art. no. A03216 - Louarn,P; Fruit,G; Budnik,E; Sauvaud,JA; Jacquey,C; Le,Quéau D; Rème,H; Lucek,E; Balogh,A (JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS, 2004)