Subject: Black holes might actually be Generic Objects of Dark Energy - Comments and suggestions are welcome! Don't hesitate and leave a comment on our comment section down below the article!
An artist’s impression of a prehistoric black hole - Image Credit: NASA/JPL-Caltech - HDR tune by Universal-Sci
Astrophysicists normally assume that huge systems like the universe, are indifferent to details of smaller systems contained within it. Scientists from the University of Hawaii at Manoa (Kevin Croker and Joel Weiner) have shown that this hypothesis can fail when it comes to compact objects that remain after the collapse and explosion of huge stars.
The researchers have identified and fixed a subtle error that was made when utilizing Einstein's equations to model the expansion of the universe.
Croker stated that It is now apparent that general relativity can observably connect collapsed stars to the behavior of the universe as a whole, over a thousand billion billion times bigger.
One consequence of this study is that the growth rate of the universe presents data about what happens to stars at the end of their lives. Astronomers typically believe that giant stars form black holes when they perish, but this is not the only potential outcome. Approximately 50 years ago the physicist Erast Gliner suggested an alternative theory that giant stars should collapse into what could now be described as Generic Objects of Dark Energy (or GEODEs). These resemble black holes when viewed from the outside but, unlike black holes, they contain Dark Energy rather than a singularity.
The newly imaged supermassive compact object at the center of galaxy M87, might in fact be GEODEs. The Powehi GEODE, shown to scale, would be approximately 2/3 the radius of the dark region imaged by the Event Horizon Telescope. This is nearly the same size expected for a black hole. The region containing Dark Energy (green) is slightly larger than a black hole of the same mass. The properties of any crust (purple), if present, rely on the particular GEODE model. - Image Credit: EHT collaboration; NASA/CXC/Villanova University - (click to enlarge)
Dark energy was initially discovered back in 1998. Scientists determined that the expansion of the Universe is accelerating, consistent with the presence of a uniform contribution of dark energy. Two teams of astronomers used eight telescopes and independently confirmed the expansion. Back then, they didn't identify that generic objects of dark energy could contribute in this way. With the fixed formalism, the Hawaiian researchers showed that if a small portion of the oldest stars collapsed into GEODEs, instead of black holes, their averaged input today would naturally produce the necessary uniform dark energy.
Three years ago LIGO observed two black holes colliding by monitoring gravitational waves. Colliding double black hole systems were assumed to exist. The colliding systems in question, however, where approximately five times larger than predicted. The results of this recent study might also apply to this mystery. The authors wondered if LIGO in actuality witnessed a double GEODE collision and not two black holes. They discovered that GEODEs develop together with the universe during the time leading up to such clashes. When the collisions transpire, the resulting GEODE masses become 4 to 8 times larger. This might better explain what LIGO-Virgo observed.
Croker and Weiner have stated that they expect to see plenty of occasions to test their theory in the future with real-world observations. We will see if it holds up, but one thing is for sure, a very interesting idea.
Sources and further reading: Implications of Symmetry and Pressure in Friedmann Cosmology. I. Formalism / University of Hawaii at Manoa press release / Dark energy
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