Tom Chang is known for his contributions in the physics of complexity, self-organized criticality and charged particle acceleration processes in space. He has directed the activities of theoretical geocosmo plasma physics at MIT for 35 years. He was a senior visitor of the University of Cambridge and an Honorary Research Fellow of the Harvard University’s Lyman Laboratory. He is a Senior Fellow of the American Physical Society, served as the President of the Society of Engineering Science and for many years as Editor of the international journal, Plasma Physics. He was the editor-in-chief of the popularly referenced AGU monograph: Ion acceleration processes in the magnetosphere and ionosphere, co-editor of the AGU monograph: Space plasmas: coupling between small and medium scale processes, lead editor of the JASTP special issue: Forced and self-organized criticality, the series editor of the SPI conference proceedings series: Physics of space plasmas, and associate editor of the AGU journal: Reviews of Geophysics.

Recently, I participated in the development of an innovative theory of complexity phenomena in space and astrophysical plasmas using the concepts of self-organized criticality, topological phase transitions, and multifractal measures. In particular, theoretical techniques using the dynamic renormalization group have been incorporated in the analytical calculations. The new method, ROMA (rank-ordered multifractal analysis) accurately and quantitatively characterizes the observed or simulated intermittent fluctuations in terms of generalized crossover invariant functions and has been applied to the solar wind, the cusp and magnetosheath, the auroral region of the magnetosphere, and currently to the very large structures of the Universe.

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Research Collaborator: David Tetreault 
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