The theoretical physicist Rafael Sorkin died on September 12, 2026, at his home in Kitchener, Ontario, the Perimeter Institute has announced. He is best known as one of the main developers of causal set theory, an approach to quantum gravity in which spacetime is fundamentally discrete. Nearly a decade before the accelerating expansion of the universe was discovered in 1998, he predicted that causal sets would give rise to an "everpresent" cosmological constant. He also introduced entanglement entropy as a possible explanation for black hole entropy
