Quantum radiation from a sandwich black hole

Understand

We discuss quantum radiation of a massless scalar field from a spherically symmetric nonsingular black hole with finite lifetime.

• Namely, we discuss a sandwich black-hole model, where a black hole is originally created by a collapse of a null shell of mass $M$, and later, after some time $\Delta V$, it is disrupted by the collapse of the other shell with negative mass $-M$.
• We assume that between the shells the metric is static and either coincides with the Hayward metric or with a special generalization of it.
• We show that in both cases for sufficiently large parameter $\Delta V$ the radiation after the formation of the black hole practically coincides with the Hawking result.