STRUCTURE OF EIGENSTATES AND LOCAL SPECTRAL DENSITY-OF-STATES - A 3-ORBITAL SCHEMATIC SHELL-MODEL

The average shape of the spectral local density of states (LDOS) and e igenfunctions (EFs) has been studied numerically for a conservative dy namical model (three-orbital Lipkin-Meshkov-Glick model) that can exhi bit strong chaos in the classical limit. Attention is paid to the comp arison of the shape of the LDOS with that known for random matrix mode ls, as well as to the shape of the EFs, for different values of the pe rturbation strength. The classical counterparts of the LDOS has also b een studied and found to be in remarkable agreement with the quantum c alculations. Finally, by making use of a generalization of Brillouin-W igner perturbation expansion, the form of the long tails of the LDOS a nd EFs is given analytically and confirmed numerically.