Eshel Ben-Jacob (full name Eshel Refael Ben-Jacob Breslav; Hebrew: אשל רפאל בן-יעקב‎ 13 April 1952 – 5 June 2015), was a theoretical and experimental physicist at Tel Aviv University, holder of the Maguy-Glass Chair in Physics of Complex Systems, and Fellow of the Center for Theoretical Biological Physics (CTBP) at Rice University. During the 1980s he became a leader in the theory of self-organization and pattern formation in open systems, later extending this work to adaptive complex systems and biocomplexity. In the late 1980s, he turned to study of bacterial self-organization, He developed new pattern forming bacteria species, becoming a pioneer in the study of bacterial intelligence and social behaviors of bacteria.