The 2026 Nobel Prize in Physics has been awarded to Francis Halzen for his work on the IceCube Neutrino Observatory and the discovery of high-energy cosmic neutrinos.

The Royal Swedish Academy of Sciences announced the prize on October 6. Halzen is the sole recipient, an unusual distinction in an era when physics prizes are often shared.

Halzen is a Belgian-American physicist at the University of Wisconsin-Madison. He first proposed using Antarctic ice to detect neutrinos in 1988.

IceCube is the world's largest neutrino telescope. It has no mirror or lens. Instead, it is built into a cubic kilometre of Antarctic ice packed with thousands of light sensors.

The observatory was completed in 2011. In 2013, it reported the first evidence of high-energy neutrinos from beyond the solar system.

Neutrinos are ghost-like particles that barely interact with matter. Because they travel in straight lines, they can point back to the universe's most violent events, including black holes.

The prize carries 12 million Swedish kronor, about 1.2 million dollars. The medals will be presented by Sweden's king in Stockholm on December 10.

Last year's physics prize went to John Clarke, Michel Devoret and John Martinis for work on quantum mechanical tunnelling.