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)