“If you jump onto and then down from a carousel, you can steal energy from the carousel,” states co-author Salvatore Vitale. “These bosons do the same thing to a black hole.” Credit: Jose-Luis Olivares, MIT
Certain ultralight bosons would be anticipated to put the brakes on great voids, however brand-new outcomes reveal no such downturn.
Ultralight bosons are theoretical particles whose mass is anticipated to be less than a billionth the mass of an electron. They communicate fairly little with their environments and have so far avoided searches to validate their presence. If they exist, ultralight bosons such as axions would likely be a kind of dark matter, the mystical, undetectable things that comprises 85 percent of the matter in deep space.
Now, physicists at MIT’s LIGO Laboratory have actually looked for ultralight bosons utilizing great voids — items that are mind-bending orders of magnitude more enormous than the particles themselves. According to the forecasts of quantum theory, a great void of a particular mass ought to draw in clouds of ultralight bosons, which in turn needs to jointly decrease a great void’s spin. If the particles exist, then all great voids of a specific mass ought to have fairly low spins.
But the physicists have actually discovered that 2 formerly found great voids are spinning too quickly to have actually been impacted by any ultralight bosons. Because of their big spins, the great voids’ presence eliminate the presence of ultralight bosons with masses in between 1.3×10-13 electronvolts and 2.7×10-13 electronvolts — around a quintillionth the mass of an electron.
The group’s outcomes, released on April 14, 2021, in Physical Review Letters, additional narrow the look for axions and other ultralight bosons. The research study is likewise the very first to utilize the spins of great voids found by LIGO and Virgo, and gravitational-wave information, to search for dark matter.
“There are different types of bosons, and we have probed one,” states co-author Salvatore Vitale, assistant teacher of physics at MIT. “There may be others, and we can apply this analysis to the growing dataset that LIGO and Virgo will provide over the next few years.”
Vitale’s co-authors are lead author Kwan Yeung (Ken) Ng, a college student in MIT’s Kavli Institute for Astrophysics and Space Research, together with scientists at Utrecht University in the Netherlands and the Chinese University of Hong Kong.
A carousel’s energy
Ultralight bosons are being looked for throughout a big series of super-light masses, from 1×10-33 electronvolts to 1×10-6 electronvolts. Scientists have actually up until now utilized tabletop experiments and astrophysical observations to eliminate slivers of this broad area of possible masses. Since the early 2000s, physicists proposed that great voids might be another way of discovering ultralight bosons, due to an impact called superradiance.
If ultralight bosons exist, they might communicate with a great void under the ideal situations. Quantum theory presumes that at an extremely little scale, particles cannot be explained by classical physics, or perhaps as specific items. This scale, called the Compton wavelength, is inversely proportional to the particle mass.
As ultralight bosons are remarkably light, their wavelength is anticipated to be remarkably big. For a particular mass series of bosons, their wavelength can be similar to the size of a great void. When this takes place, superradiance is anticipated to rapidly establish. Ultralight bosons are then developed from the vacuum around a great void, in amounts big enough that the small particles jointly drag out the great void and decrease its spin.
“If you jump onto and then down from a carousel, you can steal energy from the carousel,” Vitale states. “These bosons do the same thing to a black hole.”
Scientists think this boson slow-down can take place over numerous thousand years — fairly rapidly on astrophysical timescales.
“If bosons exist, we would expect that old black holes of the appropriate mass don’t have large spins, since the boson clouds would have extracted most of it,” Ng states. “This implies that the discovery of a black hole with large spins can rule out the existence of bosons with certain masses.”
Spin up, spin down
Ng and Vitale used this thinking to great void measurements made by LIGO, the Laser Interferometer Gravitational-wave Observatory, and its buddy detector Virgo. The detectors “listen” for gravitational waves, or reverberations from far-off catastrophes, such as combining great voids, called binaries.
In their research study, the group browsed all 45 great void binaries reported by LIGO and Virgo to date. The masses of these great voids — in between 10 and 70 times the mass of the sun — suggest that if they had actually engaged with ultralight bosons, the particles would have been in between 1×10-13 electronvolts and 2×10-11 electronvolts in mass.
For every great void, the group determined the spin that it ought to have if the great void was spun down by ultralight bosons within the matching mass variety. From their analysis, 2 great voids stood apart: GW190412 and GW190517. Just as there is an optimum speed for physical items — the speed of light — there is a leading spin at which great voids can turn. GW190517 is spinning at near to that optimum. The scientists determined that if ultralight bosons existed, they would have dragged its spin down by an element of 2.
“If they exist, these things would have sucked up a lot of angular momentum,” Vitale states. “They’re really vampires.”
The scientists likewise represented other possible circumstances for producing the great voids’ big spins, while still enabling the presence of ultralight bosons. For circumstances, a great void might have been spun down by bosons however then consequently accelerated once again through interactions with the surrounding accretion disk — a disk of matter from which the great void might draw up energy and momentum.
“If you do the math, you find it takes too long to spin up a black hole to the level that we see here,” Ng states. “So, we can safely ignore this spin-up effect.”
In other words, it’s not likely that the great voids’ high spins are because of an alternate circumstance in which ultralight bosons likewise exist. Given the masses and high spins of both great voids, the scientists had the ability to eliminate the presence of ultralight bosons with masses in between 1.3×10-13 electronvolts and 2.7×10-13 electronvolts.
“We’ve basically excluded some type of bosons in this mass range,” Vitale states. “This work also shows how gravitational-wave detections can contribute to searches for elementary particles.”
Reference: “Constraints on Ultralight Scalar Bosons within Black Hole Spin Measurements from the LIGO-Virgo GWTC-2” by Ken K. Y. Ng, Salvatore Vitale, Otto A. Hannuksela and Tjonnie G. F. Li, 14 April 2021, Physical Review Letters.
DOI: 10.1103/PhysRevLett.126.151102
This research study was supported, in part, by the National Science Foundation.
