物理学：ニュートリノが助ける量子重力効果の探索

The structure of space–time is investigated using neutrinos, as presented in a paper published in Nature Physics. The findings, revealed by the IceCube Collaboration, may enable insights into the theory of quantum gravity, which aims to describe gravity using the principles of quantum mechanics.

Neutrinos from far-away astrophysical sources, such as blazars, travel almost unperturbed to Earth. On their journey through the Universe, neutrinos might pass through regions whose structure deviates from our understanding of space–time. A possible cause for such changes in space–time is quantum gravity, which could leave imprints in the features of neutrinos.

The IceCube Collaboration, with its detector located in the depths of the Antarctic Ice Sheet, used astrophysical neutrinos to search for changes in the structure of space–time. The team analysed more than seven years of data, finding no signs of a modified structure of space–time imprinted in the features of the neutrinos. Their results provide insights into models that could lead to such modifications in a region where quantum gravity is expected to play a role.

In an accompanying News & Views, Giulia Gubitosi concludes that the “impressive sensitivity reached by the IceCube Collaboration marks a milestone in the development of quantum gravity phenomenology with astrophysical neutrinos.”