S.Ansoldi1
Dipartimento di Fisica Teorica dell'Università,
and
I.N.F.N. Sezione di Trieste,
Strada Costiera 11, I-34014 Miramare (TS), Italy
We study the dynamics of a spherically symmetric dust shell
separating two spacetime domains, the interior one
being a part of the de Sitter spacetime and the exterior one
having the extremal Reißner-Nordström
geometry. Extending the ideas of previous works on the subject,
we show that the it is possible to determine the
(metastable) WKB quantum states of this gravitational system.