HOW FAST DOES INFORMATION LEAK OUT FROM A BLACK-HOLE

Hawking's radiance departs from blackbody form due to the mode dependence of the barrier penetration factors. Thus it is not the maximal entropy radiation for given energy. To check whether this entropic deficiency is consistent with the possibility that the radiance may carry information about the quantum state in the far past, we compare estimates of the actual entropy emission rate with the maximal possible one for the same power. Standard quantum communication theory then shows that the permitted information outflow rate can be as large as the rate of black hole entropy decrease. The initial information may thus gradually leak out during the evaporation.