Test of universality of free fall for neutrinos

The universality of free fall, fundamental to metric theories of gravity, asserts the equality between inertial and gravitational mass, implying that all particles experience equal gravitational fall regardless of their mass. While it is widely accepted for all particles and photons, its applicability to neutrinos, due to their minimal interactions, remains uncertain. Neutrinos, though predicted to be massless, exhibit flavor-changing behavior and have nonzero mass, making it crucial to determine if they adhere to the principle. This paper introduces evidence from supernova 1987a observations suggesting that the time difference between correlated photons and neutrinos supports the universality of free fall for neutrinos with an accuracy of 2.7 part of a thousand.