Fuzzball (string theory)

Fuzzballs are hypothetical objects in superstring theory, intended to provide a fully quantum description of the black holes predicted by general relativity.

The fuzzball hypothesis dispenses with the singularity at the heart of a black hole by positing that the entire region within the black hole's event horizon is actually an extended object: a ball of strings, which are advanced as the ultimate building blocks of matter and light. Under string theory, strings are bundles of energy vibrating in complex ways in both the three familiar dimensions of space as well as in extra dimensions.[1] Fuzzballs provide resolutions to two major open problems in black hole physics. First, they avoid the gravitational singularity that exists within the event horizon of a black hole. General relativity predicts that at the singularity, the curvature of spacetime becomes infinite, and it cannot determine the fate of matter and energy that falls into it. Physicists generally believe that the singularity is not a real phenomenon, and proposed theories of quantum gravity, such as superstring theory, are expected to explain its true nature.[2] Second, they resolve the black hole information paradox: the quantum information of matter falling into a black hole is trapped behind the event horizon, and seems to disappear from the universe entirely when the black hole evaporates due to Hawking radiation. This would violate a fundamental law of quantum mechanics requiring that quantum information be conserved.[1][3]

As no direct experimental evidence supports either string theory in general or fuzzballs in particular, both are products purely of calculations and theoretical research.[4][better source needed] However, the existence of fuzzballs may be testable through gravitational-wave astronomy.[5]

  1. ^ a b "The Fuzzball Fix for a Black Hole Paradox", Jennifer Ouellette, Quanta Magazine, (June 23, 2015)
  2. ^ Nadis, Steve (2 December 2019). "Black Hole Singularities Are as Inescapable as Expected". quantamagazine.org. Quanta Magazine. Archived from the original on 14 April 2020. Retrieved 22 April 2020.
  3. ^ "The fuzzball paradigm for black holes: FAQ", Samir D. Mathur, (January 22, 2009) (395 KB)
  4. ^ "Why String Theory?", Joseph Conlon, CRC Press, (2016) ISBN 978-1482242478
  5. ^ "A Way to Experimentally Test String Theory's 'Fuzzball' Prediction", APS Journals, (September 16, 2021)