2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/229845We theoretically study the collective excitations of an ideal gas confined in an isotropic harmonic trap. We give an exact solution to the Boltzmann-Vlasov equation; as expected for a single-component system, the associated mode frequencies are integer multiples of the trapping frequency. We show that the expressions found by the scaling ansatz method are a special case of our solution. Our findings, however, are most useful in case the trap contains more than one phase: we demonstrate how to obtain the oscillation frequencies in case an interface is present between the ideal gas and a different phase.4 pages, submitted to special issue of Eur. Phys. J. B "Novel Quantum Phases and Mesoscopic Physics in Quantum Gases"Other Condensed MatterStatistical Mechanicstext