Using data from NASA’s Fermi Gamma-ray Space Telescope and the IceCube Neutrino Observatory, astrophysicists have found preliminary evidence for gamma-ray burst neutrinos being sped up or slowed down by quantum spacetime properties.
In addition to its implications for astrophysics, the hunt for neutrinos originating from gamma-ray bursts could also be significant in quantum-gravity research, as they are excellent probes of the microscopic fabric of spacetime.
Some previous studies based on neutrinos observed by the IceCube Neutrino Observatory found intriguing preliminary evidence that some of them might be gamma-ray burst neutrinos whose travel times are affected by quantum properties of spacetime that would slow down some of the neutrinos while speeding up others.
The IceCube Collaboration recently significantly revised the estimates of the direction of observation of their neutrinos, and University of Naples Professor Giovanni Amelino-Camelia and his colleagues investigated how the corrected directional information affects the results of the previous quantum-spacetime-inspired analyses.
“We analyzed a quantum-gravity model of particle propagation,” the researchers explained.
“We explored how the speed of ultrarelativistic particles changes as their energy increases.”
“This phenomenon is expected to be incredibly small, relative to the ratio between particle energy and the Planck scale.”
“However, when observing astrophysical sources that are very distant, this effect can accumulate and become noticeable.”
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| NASA’s Fermi Gamma-ray Space Telescope (top left) and the IceCube Neutrino Observatory (sensor strings, bottom). Image credit: NASA / Fermi / Aurore Simonnet, Sonoma State University. |
In their research, the authors analyzed gamma-ray bursts detected by Fermi and high-energy neutrinos detected by the IceCube Neutrino Observatory.
Their goal was to test the hypothesis that certain neutrinos and gamma-ray bursts share a common origin but are observed at different times due to the energy-dependent decrease in speed.
“By merging data from IceCube and Fermi, we discovered preliminary indications affirming quantum gravity models that anticipate this phenomenon,” Professor Amelino-Camelia said.
“This represents a noteworthy breakthrough in the realm of quantum gravity investigation, as it marks the initial instance of uncovering statistical evidence supportive of quantum gravity at such a level.”
“Although these findings are preliminary, they establish a robust basis for conducting further in-depth explorations as we collect additional data from our gamma-ray and neutrino telescopes.”
“Even in the event that future data fails to corroborate this phenomenon, our discoveries would still impose rigorous constraints on the parameters of pertinent models.”
“This outcome alone would already signify a remarkable and infrequent stride in the realm of quantum gravity research.”
Sources:
Published online June 12, 2023 in the journal Nature Astronomy: G. Amelino-Camelia et al. Could quantum gravity slow down neutrinos? Nat Astron ; doi: 10.1038/s41550-023-01993-z
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