7 research outputs found
Thermal radiation of various gravitational backgrounds
We present a simple and general procedure for calculating the thermal
radiation coming from any stationary metric. The physical picture is that the
radiation arises as the quasi--classical tunneling of particles through a
gravitational barrier. We show that our procedure can reproduce the results of
Hawking and Unruh radiation. We also show that under certain kinds of
coordinate transformations the temperature of the thermal radiation will change
in the case of the Schwarzschild black holes. In addition we apply our
procedure to a rotating/orbiting system and show that in this case there is no
radiation, which has experimental implications for the polarization of
particles in circular accelerators.Comment: 6 pages revtex, added references, publication version. To be
published IJMP
Comments on anomaly versus WKB/tunneling methods for calculating Unruh radiation
In this Letter we make a critique of, and comparison between, the anomaly
method and WKB/tunneling method for obtaining radiation from non-trivial
spacetime backgrounds. We focus on Rindler spacetime (the spacetime of an
accelerating observer) and the associated Unruh radiation since this is the
prototype of the phenomena of radiation from a spacetime, and it is the
simplest model for making clear subtle points in the tunneling and anomaly
methods. Our analysis leads to the following conclusions: (i) neither the
consistent and covariant anomaly methods gives the correct Unruh temperature
for Rindler spacetime and in some cases (e.g. de Sitter spacetime) the
consistent and covariant methods disagree with one another; (ii) the tunneling
method can be applied in all cases, but it has a previously unnoticed temporal
contribution which must be accounted for in order to obtain the correct
temperature.Comment: 13 pages, 0 figures, revtex4, To be published PLB. Critic of detailed
balance dropped and reference added which shows how detailed balance works if
one correctly takes into account the temporal piece. Discussion added about
temporal contribution giving P_abs=1 condition added showing why "complex
integration" constant is not neede