324 research outputs found
Dynamically assisted Sauter-Schwinger effect in inhomogeneous electric fields
Via the worldline instanton method, we study electron-positron pair creation
by a strong electric field of the profile superimposed by a
weaker pulse . If the temporal Keldysh parameter
exceeds a threshold value which depends on the spatial Keldysh parameter , we
find a drastic enhancement of the pair creation probability -- reporting on
what we believe to be the first analytic non-perturbative result for the
interplay between temporal and spatial field dependences in the
Sauter-Schwinger effect.Comment: 13 pages, 4 figure
Quantum toy model for black-hole back-reaction
We propose a simple quantum field theoretical toy model for black hole
evaporation and study the back-reaction of Hawking radiation onto the classical
background. It turns out that the horizon is also ``pushed back'' in this
situation (i.e., the interior region shrinks) but this back-reaction is not
caused by energy conservation but by momentum balance. The effective heat
capacity and the induced entropy variation can have both signs -- depending on
the parameters of the model. PACS: 04.62.+v, 04.70.Dy.Comment: 4 page
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