Spectral properties of spherically confined dusty plasma crystals
  A combined theoretical and experimental analysis of the normal modes of three-dimensional spherially confined Yukawa clusters is presented. Particular attention is paid to the breathing mode and the existence of multiple monopole oscillations in Yukawa systems. Finally, the influence of dissipation on the mode spectrum is investigated. 
C. Henning, H. K\"ahlert, P. Ludwig, A. Melzer, M. Bonitz