Roy J. Glauber, physicist

Roy Glauber invented the class of stochastic matrices that obey detailed balance. In the simplest case this means that the transition probability forward from one energy-level to another, in an ambient isothermal environment, must be related to the transition probability in the reverse direction by the Boltzmann factor exp(-beta E), where E is the difference in energy of the two levels. See also Glauber and his colleagues here.