Rayleigh–Jeans
/ˌreɪlɪˈdʒiːns/Physics
noun
Used attributive with reference to an approximation to Planck's radiation law that is valid only at long wavelengths and states that the flux of radiation from a black body at any particular wavelength is proportional to its temperature divided by the fourth power of the wavelength.
Origin
Early 20th century; earliest use found in Proceedings of the Royal Society of London. From the title of J. W. Strutt, 3rd Baron Rayleigh + the name of Sir James Hopwood Jeans, English physicist and astronomer.