HAWKING RADIATION - A PARTICLE PHYSICS PERSPECTIVE

It has recently become fashionable to regard black holes as elementary particles. By taking this suggestion reasonably seriously it is possi ble to cobble together an elementary particle physics based on estimat e for the decay rate (black hole)i --> (black hole)f + (massless quant um). This estimate of the spontaneous emission rate contains two free parameters which may be fixed by demanding that the high energy end of the spectrum of emitted quanta match a black body spectrum at the Haw king temperature. The calculation, though technically trivial, has imp ortant conceptual implications: (1) The existence of Hawking radiation from black holes seems ultimately dependent only on the fact that mas sless quanta (and all other forms of matter) couple to gravity. (2) Th e essentially thermal nature of the Hawking spectrum seems to depend o nly on the fact that the number of internal states of a large mass bla ck hole is enormous. (3) Remarkably, the resulting formula for the dec ay rate gives meaningful answers even when extrapolated to low mass bl ack holes. The analysis seems to support the scenario of complete evap oration as the end point of the Hawking radiation process (no naked si ngularity, no stable massive remnant).