Abstract
We present an analytic derivation of Hawking radiation for an arbitrary (spatial) dispersion relation as a model for ultrahigh-energy deviations from general covariance. It turns out that the Hawking temperature is proportional to the product of the group and phase velocities evaluated at the frequency of the outgoing radiation far away, which suggests that Hawking radiation is basically a low-energy phenomenon. Nevertheless, a group velocity growing too fast at ultrashort distances would generate Hawking radiation at ultrahigh energies (“ultraviolet catastrophe”) and hence should not be a realistic model for the microscopic structure of quantum gravity.
- Received 19 May 2008
DOI:https://doi.org/10.1103/PhysRevD.78.041504
©2008 American Physical Society