Physik - Open Access LMU - Teil 02/02

Phases of information release during black hole evaporation


Listen Later

In a recent article, we have shown how quantum fluctuations of the background geometry modify Hawking's density matrix for black hole (BH) radiation. Hawking's diagonal matrix picks up small off-diagonal elements whose influence becomes larger with the number of emitted particles. We have calculated the "time-of-first-bit", when the first bit of information comes out of the BH, and the "transparency time", when the rate of information release becomes order unity. We have found that the transparency time is equal to the "Page time" when the BH has lost half of its initial entropy to the radiation, in agreement with Page's results. Here, we improve our previous calculation by keeping track of the time of emission of the Hawking particles and their back-reaction on the BH. Our analysis reveals a new time scale, the radiation "coherence time", which is equal to the geometric mean of the evaporation time and the light crossing time. We find, as for our previous treatment, that the time-of-first-bit is equal to the coherence time, which is much shorter than the Page time. But the transparency time is now much later than the Page time, just one coherence time before the end of evaporation. Close to the end, when the BH is parametrically of Planckian dimensions but still large, the coherence time becomes parametrically equal to the evaporation time, thus allowing the radiation to purify. We also determine the time dependence of the entanglement entropy of the early and late-emitted radiation. This entropy is small during most of the lifetime of the BH, but our qualitative analysis suggests that it becomes parametrically maximal near the end of evaporation.
...more
View all episodesView all episodes
Download on the App Store

Physik - Open Access LMU - Teil 02/02By Ludwig-Maximilians-Universität München


More shows like Physik - Open Access LMU - Teil 02/02

View all
Tonspur Forschung by Annik Rubens

Tonspur Forschung

3 Listeners

Einführung in die Ethnologie by Prof. Dr. Frank Heidemann

Einführung in die Ethnologie

0 Listeners

Theoretical Physics Schools (ASC) by The Arnold Sommerfeld Center for Theoretical Physics (ASC)

Theoretical Physics Schools (ASC)

2 Listeners

MCMP – Mathematical Philosophy (Archive 2011/12) by MCMP Team

MCMP – Mathematical Philosophy (Archive 2011/12)

6 Listeners

Hegel lectures by Robert Brandom, LMU Munich by Robert Brandom, Axel Hutter

Hegel lectures by Robert Brandom, LMU Munich

6 Listeners

MCMP – Metaphysics and Philosophy of Language by MCMP Team

MCMP – Metaphysics and Philosophy of Language

2 Listeners

MCMP – Philosophy of Science by MCMP Team

MCMP – Philosophy of Science

1 Listeners

Sommerfeld Lecture Series (ASC) by The Arnold Sommerfeld Center for Theoretical Physics (ASC)

Sommerfeld Lecture Series (ASC)

0 Listeners

MCMP by MCMP Team

MCMP

2 Listeners

Women Thinkers in Antiquity and the Middle Ages - SD by Peter Adamson

Women Thinkers in Antiquity and the Middle Ages - SD

0 Listeners