Theodore Edward "Ted" Harris (11 January 1919 – 3 November 2005) was an American mathematician known for his research on stochastic processes, including such areas as general state-space Markov chains (often now called Harris chains), the theory of branching processes and stochastic models of interacting particle systems such as thecontact process. The Harris inequality in statistical physics and percolation theory is named after him.He received his Ph.D.