Tunnelling from black holes and tunnelling into white holes

Understand

Hawking radiation is nowadays being understood as tunnelling through black hole horizons.

• Here, the extension of the Hamilton-Jacobi approach to tunnelling for non-rotating and rotating black holes in different non-singular coordinate systems not only confirms this quantum emission from black holes but also reveals the new phenomenon of absorption into white holes by quantum mechanical tunnelling.
• The role of a boundary condition of total absorption or emission is also clarified.