Binary black holes recently discovered by the Ligo-Virgo collaboration could be primordial entities that formed just after the Big Bang. Primordial black hole binaries were discussed extensively in the 1990s. However, interest in them waned when observations implied that their number was limited
New scenario from Japan offers clues about the early universe. Binary black holes recently discovered by the LIGO-Virgo collaboration could be primordial entities that formed just after the Big Bang. If further data support this observation, it could mark the first confirmed finding of a primordial black hole, guiding theories about the beginnings of the universe.
In February, the LIGO-Virgo collaboration announced the first successful detection of gravitational waves.”The detected gravitational waves were created from a merger of 2 black holes 30 times the mass of the Sun. It’s extremely rare for such massive black holes to form in the present-day universe,” says Takahiro Tanaka of Kyoto University. “After this announcement, many astrophysicists started considering how such heavy black holes were created, and how such black hole binaries were formed.”
As a starting point, the team hypothesized that primordial black holes – formed following the Big Bang were distributed randomly in space. “The universe was extremely hot and dense when it was first born. Primordial black holes came into being when gravitational collapse happened in regions which were especially dense,” explains Tanaka. “They have a completely different origin from black holes that form from celestial bodies.”
The Laser Interferometer Gravitational-Wave Observatory (Ligo) detected gravitational waves radiating from two black holes that crashed together about 1.3 billion years ago, simulation pictured. Researchers from Kyoto University have suggested the two black holes detected by Ligo could be ‘primordial’ black holes, instead of traditional black holes Read more: http://www.dailymail.co.uk/sciencetech/article-3712650/Have-new-kind-black-hole-Gravitational-waves-come-primordial-objects-old-universe.html#ixzz4G0HFBcpw Follow us: @MailOnline on Twitter | DailyMail on Facebook
Based on general relativity, the research team evaluated how often black holes merge in the present epoch. They found that the team’s observational data on merger frequencies would fall in to place if the binaries were primordial, and if they constitute a 1/1000 of all dark matter in the universe. To date, no one has found any primordial black holes, possibly making the LIGO-Virgo observations the first of their kind.
If primordial black holes exist today in large enough numbers, they could make up dark matter, the researchers suggest. The black holes detected by Ligo have the perfect mass to fit with a theory that suggests dark matter is made up of these primordial black holes. Artist’s impression of a black hole shown
“Theoretical models about the beginnings of the universe are still hotly contested. Some models necessarily predict the existence of primordial black holes, so their discovery could help unlock important clues about the universe’s early days,” says Tanaka. “When enough observational data related to black hole binaries has accumulated, it will become possible to confirm whether these are truly primordial.” http://www.eurekalert.org/pub_releases/2016-07/ku-dtl072616.php
https://arxiv.org/abs/1603.08338
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