The gravitational waves discovered by the detectors of the LIGO observatory could have arisen not in the course of mergers of black holes, but as a result of the "collapse" of the so-called wormholes, tunnels in the fabric of space-time, physicists say in an article published in the journal Physical Review D.
“The special 'tremor' that occurs in the last stages of the merging of black holes gradually disappears if the object generated by them has an event horizon. In the event that it does not exist, as in wormholes, then these vibrations do not disappear completely - they cause a kind of echo, a series of bursts, similar to how if we shouted into a well,”says Pablo Bueno (Pablo Bueno) from the Catholic University of Leuven (Belgium).
The LIGO gravitational wave detector was built in 2002 according to projects and plans that were developed by Kip Thorn, Rainer Weiss and Ronald Drever in the late 1980s. At the first stage of its work, which lasted 8 years, LIGO was unable to detect "Einstein's" oscillations of space-time, after which the detector was turned off and the next 4 years, scientists spent on updating and increasing the sensitivity.
These efforts paid off - in September 2015, almost immediately after the inclusion of the updated LIGO, scientists discovered a burst of gravitational waves generated by merging black holes with a total mass of 53 Suns. In 2016, Russian and foreign participants in the project discovered two more traces of merging black holes, and last year - two other similar events and a burst born of the merger of neutron stars.
The unusually large mass of these objects, as well as some of their other properties, made Bueno and his colleagues wonder if they were in fact black holes. The fact is that the theory of relativity and its extensions assume that similar gravitational waves can arise as a result of the collapse or merging of other exotic objects, such as "wormholes".
This is how scientists call a kind of “tunnels” connecting two points located in different regions of space or time. In order for such a channel in the structure of space-time to exist, some exotic form of matter is needed, which would have a negative energy density, or an object similar to a black hole in size and mass.
These objects, as Bueno and his colleagues explain, will have one "plus" compared to black holes - they will not have an event horizon, whose existence is still extremely difficult to explain in the framework of quantum physics. Its absence, as physicists have long assumed, will change the behavior of gravitational waves generated by "wormholes."
The authors of the article uncovered these changes and tried to find them in the data collected by LIGO by creating a computer model of such a spatial tunnel. As shown by these calculations, the primary burst of gravitational waves generated by a black hole or "wormhole" actually completely coincides, which is why it is impossible to distinguish them from each other at this stage.
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On the other hand, similar differences emerge in the last stage of this cosmic cataclysm, which astronomers call “ringdown”. Typically, such a gravitational "echo" quickly disappears when observing black holes due to the fact that her event horizon helps her quickly get rid of these fluctuations.
This does not happen in the case of "wormholes" - they will continue to periodically emit bursts of gravitational waves with a strictly defined spectrum and strength. Such an echo, as scientists note, will exist tens of times longer than the primary burst of space-time oscillations, but at the same time it will be noticeably weaker in strength.
So far, Bueno admits, there is no trace of such a "gravitational echo" in the data from LIGO, but the observatory's detector update, planned for this year, may enable it to "see" these faint but extremely important signals for scientists that will help them reconcile the theory. relativity and quantum physics..
