An Accelerating Reference Frame for Electromagnetic Waves in a Rapidly Growing Plasma: Unruh Radiation and the Dynamic Casimir Effect

Abstract

In 1974, Hawking showed1 that Black Holes can evaporate by the emission of low temperature thermal radiation, now named Hawking Radiation. Shortly thereafter, a closely related effect called Unruh Radiation became apparent. According to Unruh2 and Davies2, observers of the electromagnetic field in an accelerating reference frame should see thermal radiation at a temperature T: where a is the acceleration relative to an inertial frame, c is the speed of light and ħ and K are Planck's and Boltzmann's constant respectively. In a frame accelerating at g= 980 cm/sec2, equivalent to the acceleration experienced at the earth's surface3, this thermal radiation is at a temperature of only 4× 10−20 °K. Therefore, physicists hoping to observe this radiation, have sought out systems being subjected to extreme acceleration. For example, J. S. Bell has suggested4 that the spin depolarization of electrons accelerating around a synchrotron storage ring may be interpreted as being due to such radiation.