Quantum shape-phase transitions in finite nuclei are considered in the
framework of the interacting boson model. Critical-point Hamiltonians for
first- and second-order transitions are identified by resolving them into
intrinsic and collective parts. Suitable wave functions and finite-N estimates
for observables at the critical-points are derived.Comment: 6 pages, 2 figures, Proc. 2nd Int. Conf. on "Collective Motion in
Nuclei under Extreme Conditions" (COMEX 2), June 20-23, 2006, Sankt Goar,
German