How is the singularity of a Black Hole treated in Loop Quantum gravity ? Does it go away ? And if it does, what's after the event horizon ?


2 Answers 2


There has been some funny progress recently, as described in a paper by Ashtekar, Olmedo and Singh, about which Rovelli wrote this article: https://physics.aps.org/articles/v11/127

Apparently, loop quantum gravity predicts that evolving black holes first shrink to Planck-sized objects, then turn into white holes. These are basically the time-reverse of black holes, objects that spit energy and matter out into their environment.

LQG seems to like this idea of replacing singularities as they occur in GR by 'bounces', as it also predicts a Big Bounce, instead of a Big Bang, as the origin of our current universe.

EDIT: to more precisely answer the original question, the actual singularity within the black hole indeed goes away in LQG, and is replaced with some small region in which the Einstein equations are corrected by quantum effects. In other words, there is a small ball of quantum gravity 'stuff' within the horizon, not a pointlike singularity.


The theory of loop gravity would suggest that it would only become more dense in a singularity event. So It would not go away but become very very dense. So if anything the possibility arises That after the event horizon it would either become so dense it would simply just not be detected aside from its push of gravity. So if the theory dictates these events it would be small. Yet another theory suggests that it would be a repetitious event, such as it would go through and come out some where else coming out just as it was going in. So it wouldn't go away in either but become stronger and stronger in one theory and the other it would become stronger then return.

  • $\begingroup$ Thanks for the answer, do you have a source? $\endgroup$
    – OTH
    Commented Oct 9, 2015 at 10:10
  • $\begingroup$ My source. Although I did not specify the obvious parts. Also I must apologize I couldn't comment not enough credits. $\endgroup$
    – user94762
    Commented Oct 10, 2015 at 13:39
  • $\begingroup$ @TimothyBrachna You may want to read this help-center page concerning duplicated accounts: physics.stackexchange.com/help/merging-accounts $\endgroup$ Commented Oct 10, 2015 at 16:30
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    $\begingroup$ Throughout this answer, you use the word "it." What does "it" refer to? $\endgroup$
    – user4552
    Commented Jan 13, 2020 at 1:58

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