Do black holes have hair? A new hypothesis on the nature of these celestial bodies

Sep 30, 2013

Black holes may be less simple and "clean" than how the most authoritative theoretical model describes them. This is what a group of researchers based at the International School of Advanced Studies, Trieste, and IST, Lisbon, claims in a new article appeared in Physical Review Letters. According to the scientists' calculations, these celestial bodies may actually have "hair".

A black hole. A simple and clear concept, at least according to the hypothesis by Roy Kerr, who in 1963 proposed a "clean" black hole model, which is the current theoretical paradigm. From theory to reality things may be quite different. According to a new research carried out by a group of scientists that includes Thomas Sotiriou, a physicist of the International School for Advanced Studies (SISSA) of Trieste, may be much "dirtier" than what Kerr believed.

According to the traditional model, black holes are defined by only two quantities: mass and angular momentum (a black hole rotation velocity). Once their progenitor has collapsed (a high mass star, for instance, that at the end of its life cycle implodes inwards) its memory is lost forever. All that is left is a quiescent black hole, with almost no distinctive features: all black holes, mass and angular momentum aside, look almost the same.

According to Sotiriou, things may not have occurred this way. "Black holes, according to our calculations, may have hair", explains Sotiriou, referring to a well-known statement by physicist John Wheeler, who claimed that "black holes have no hair". Wheeler meant that mass and are all one needs to describe them.

"Although Kerr's 'bald' model is consistent with General Relativity, it might not be consistent with some well-known extensions of Einstein's theory, called tensor-scalar theories", adds Sotiriou. "This is why we have carried out a series of new calculations that enabled us to focus on the matter that normally surrounds realistic black holes, those observed by astrophysicists. This matter forces the pure and simple black hole hypothesized by Kerr to develop a new 'charge' (the hair, as we call it) which anchors it to the surrounding matter, and probably to the entire Universe."

The experimental confirmation of this new hypothesis may come from the observations carried out with the interferometers, instruments capable of recording the gravitational waves. "According to our calculations, the growth of the black hole's hair," concludes Sotiriou "is accompanied by the emission of distinctive gravitational waves. In the future, the recordings by the instrument may challenge Kerr's model and broaden our knowledge of the origins of gravity."

Explore further: Capturing black hole spin could further understanding of galaxy growth

More information: link.aps.org/doi/10.1103/PhysRevLett.111.111101

add to favorites email to friend print save as pdf

Related Stories

Answers to black hole evolution beyond the horizon?

Jan 19, 2011

One of the most important predictions of Einstein's theory of General Relativity is the existence of black holes. The dynamics of these systems are not yet fully understood, but researchers from Queen Mary, ...

Recommended for you

Quest for extraterrestrial life not over, experts say

Apr 18, 2014

The discovery of an Earth-sized planet in the "habitable" zone of a distant star, though exciting, is still a long way from pointing to the existence of extraterrestrial life, experts said Friday. ...

Continents may be a key feature of Super-Earths

Apr 18, 2014

Huge Earth-like planets that have both continents and oceans may be better at harboring extraterrestrial life than those that are water-only worlds. A new study gives hope for the possibility that many super-Earth ...

Exoplanets soon to gleam in the eye of NESSI

Apr 18, 2014

(Phys.org) —The New Mexico Exoplanet Spectroscopic Survey Instrument (NESSI) will soon get its first "taste" of exoplanets, helping astronomers decipher their chemical composition. Exoplanets are planets ...

User comments : 2

Adjust slider to filter visible comments by rank

Display comments: newest first

tadchem
1 / 5 (4) Sep 30, 2013
The concept of "no hair" on a black hole simply means that it can only possess properties expressible by single quantum numbers: mass, angular momentum, net charge, and magnetic dipole moment. The black hole has no internal structure as that would require subordinate component parts which can interact with each other within the 'hole'.
Personally I believe 'gravity' waves' will never be quantized into 'gravitons' as that would be inconsistent with the mathematics of the continuum model for empty space/time.
Fleetfoot
5 / 5 (2) Oct 01, 2013
it might not be consistent with some well-known extensions of Einstein's theory, called tensor-scalar theories", adds Sotiriou.

This matter forces the pure and simple black hole hypothesized by Kerr to develop a new 'charge'


OK, they're trying to extend MOND theories to include charge. It seems they forgot GR already provides the Reissner-Nordstrom solution:

https://en.wikipe...ack_hole

More news stories

Easter morning delivery for space station

Space station astronauts got a special Easter treat: a cargo ship full of supplies. The shipment arrived Sunday morning via the SpaceX company's Dragon cargo capsule.

Making graphene in your kitchen

Graphene has been touted as a wonder material—the world's thinnest substance, but super-strong. Now scientists say it is so easy to make you could produce some in your kitchen.