4

Do the interiors of black-holes create gravitational waves and if so do these waves cause the radius of the event horizon to fluctuate as the waves pass the horizon ?

David Z
  • 76,371
vtt
  • 859
  • 1
  • 6
  • 11

1 Answers1

1

Distortions of the horizon do cause gravitational waves to radiate, an effect known as the 'ringdown' of the black hole horizon.

Effects happening inside of the interior of the blackhole cannot cause distortions of the horizon.

Zo the Relativist
  • 41,373
  • 2
  • 74
  • 143
  • 1
    Just some notes: Ringdown is the result of binary coalescence specifically. The fluctuations of the event horizon are called quasi-normal modes (QNMs). QNMs may be induced by any perturbative process (including ringdown but also, for example, a gravitational wave passing the black hole (BH) or by collapse to a BH). This is a nice (but technical) review. – user12345 Sep 11 '12 at 20:08
  • Why does the horizon not get distorted by things happening in the interior, is it because gravitational waves for example, if they originate from the interior of the black should be mapped by the ADS/CFT correspondance to the horizon ? Or why is this if I am wrong? Just curious... – Dilaton Sep 11 '12 at 21:14
  • @Dilaton: The gravitational disturbances have to obey the same laws that everything else does. Once inside the black hole, there is no future-pointing path that travels to the outer horizon. No need to evoke anything as esoteric as AdS/CFT – Zo the Relativist Sep 11 '12 at 21:23
  • Ok, thanks for the clarification, I was a bit stupid it seems :-/ – Dilaton Sep 11 '12 at 21:25
  • 2
    @Dilaton “He who asks a question is a fool for five minutes; he who does not ask a question remains a fool forever” :) – user12345 Sep 12 '12 at 09:49
  • Thanks @user16307 for the kind words ;-), I sometimes feel sooo stupid 5min after having asked a dumb question .... – Dilaton Sep 12 '12 at 10:01
  • If matter can escape a black hole as here: http://physics.stackexchange.com/questions/35506/reasons-to-suspect-that-matter-is-emitted-from-black-holes-nonthermally then surely waves can also escape. – vtt Sep 12 '12 at 11:22
  • @vtt Just because it has been claimed by one guy on physics.stackexchange doesn't make it true. Firstly, take a look at the comments to the answer, then read the "about me" on the answerer's profile page; you'll be very surprised. – user12345 Sep 12 '12 at 12:43
  • @vtt: that post is an unpublished claim that contradicts the thought of the entire astrophysics community, and is supported with a series of vague claims. Take it how you will. – Zo the Relativist Sep 12 '12 at 16:34
  • 3
    @Dilaton: there was nothing stupid above. Trying to understand is not stupid. – Zo the Relativist Sep 12 '12 at 16:34
  • @user16307 Regarding the first thing you asked in this comment section, I like to think of a black hole as the event horizon itself. The uniqueness (its "it-ness") of anything that falls into the black hole is lost, and it's physical properties (mass, information) are absorbed into the 2D surface. Then as the event horizon wobbles and waves, we may attribute all observations to the dynamics of the surface, as there is nothing beyond the surface. That is where the universe ends. – Alan Rominger Dec 10 '12 at 20:23