Unruh effect

The Unruh effect is a phenomenon in quantum field theory, which causes an accelerated observer sees itself facing with a temperature proportional to the acceleration of a black-body radiation.

The effect was predicted at the University of British Columbia in Canada in 1976 by William Unruh. An experimental verification, which is currently considered to be difficult but not impossible, is still pending.

The effect is due to the fact that the ground state of a quantum field theory in Minkowski space-time is represented in coordinates for a part of spacetime, namely the so-called Rindler wedge. The Rindler wedge corresponds to the region of spacetime in which there is, so it's half the area, which is spacelike to the origin. In this field can be used for any acceleration a coordinate system choose to rest in the observer with this acceleration. These coordinate systems correspond to different normalizations of the timelike Killing vector field of the wedges. The restriction of the ground state to such a coordinate system results in a thermodynamic equilibrium state.

The temperature T of the equivalent energy k T, which provides for uniformly accelerated the observer is:

To give an idea of ​​the magnitude of the effect: At an acceleration by gravity g = 9.81 m / s ² is the temperature of the Unruh effect only 4 · 10-20 K. For an experimental test of the effect, in which an electron is accelerated by the electric field of a laser to accelerations of up to 1026 m / s ², corresponding to a temperature of 400,000 K result.