Gravitational collapse of a radiating shell

We study the collapse of a self-gravitating and radiating shell of bosonic matter. The matter constituting the shell is quantized and the construction is viewed as a semiclassical model of possible black hole formation. It is shown that the shell internal degrees of freedom are excited by the quantum nonadiabaticity of the collapse and, consequently, on coupling them to a massless scalar field, the collapsing matter emits a burst of coherent (thermal) radiation. The back reaction on the trajectory is also estimated. ©2001 The American Physical Society