Black Hole Formation by Canonical Dynamics of Gravitating Shells: An Equatorial View

Gravitating shells lead to simple minisuperspacemodels of black hole formation by gravitational collapseof matter. I interpret here the Hajicek–Kijowskivariational principle for spacetime with a shell as a Dirac–ADM action principle along atimelike foliation including the shell as a leaf. Byreducing this action by spherical symmetry, I obtain theHamiltonian constraint of a collapsing dust shell and use it as a prelude to canonicalquantization.