Robert Devaney

Robert Luke Devaney (April 9, 1948 – November 16, 2025) was an American mathematician known for his research in dynamical systems theory. He was the Feld Family Professor of Teaching Excellence at Boston University, and served as the president of the Mathematical Association of America from 2013 to 2015. His research involved dynamical systems and fractals.

Background Devaney was born in Lawrence, Massachusetts, on April 9, 1948. He grew up in Methuen, Massachusetts,

After high school, Devaney graduated from the College of the Holy Cross in Worcester, Massachusetts, with a Bachelor of Arts in mathematics with highest honors in 1969. He then earned his Ph.D. in mathematics in 1973 from the University of California, Berkeley, under Fields medalist Stephen Smale. His doctoral dissertation was titled, "Reversible diffeomorphisms and flows".

After receiving his doctorate, Devaney was a postdoctoral research fellow at Northwestern University from 1974 to 1976.

Mathematical activities Devaney is known for formulating a simple and widely used definition of chaotic systems, one that does not need advanced concepts such as measure theory. In his 1989 book An Introduction to Chaotic Dynamical Systems, Devaney defined a system to be chaotic if it has sensitive dependence on initial conditions, it is topologically transitive (for any two open sets, some points from one set will eventually hit the other set), and its periodic orbits form a dense set. Later, it was observed that this definition is redundant: sensitive dependence on initial conditions follows automatically as a mathematical consequence of the other two properties.

Devaney hairs, a fractal structure in certain Julia sets, are named after Devaney, who was the first to investigate them.

As well as research and teaching in mathematics, Devaney's mathematical activities have included organizing one-day immersion programs in mathematics for thousands of Boston-area high school students, and consulting on the mathematics behind media productions including the 2008 film 21 and the 1993 play Arcadia.

Awards and honors In 1995, Devaney won the Deborah and Franklin Tepper Haimo Award for Distinguished University Teaching of the Mathematical Association of America. In 2002, Devaney won the National Science Foundation Director's Award for Distinguished Teaching Scholars. He was named the inaugural Feld Professor in 2010.

In 2012, he became one of the inaugurals fellows of the American Mathematical Society.

Selected publications Books Devaney is the author of books on fractals and dynamical systems including: An Introduction to Chaotic Dynamical Systems (Benjamin/Cummings 1986; 2nd ed., Addison-Wesley, 1989; reprinted by Westview Press, 2003) The Science of Fractal Images (with Barnsley, Mandelbrot, Peitgen, Saupe, and Voss, Springer-Verlag, 1988) Chaos, Fractals, and Dynamics: Computer Experiments in Mathematics (Addison-Wesley, 1990) A First Course in Chaotic Dynamical Systems: Theory and Experiment (Addison-Wesley, 1992) Fractals: A Tool Kit of Dynamics Activities (with J. Choate and A. Foster, Key Curriculum Press, 1999) Iteration: A Tool Kit of Dynamics Activities (with J. Choate and A. Foster, Key Curriculum Press, 1999) Chaos: A Tool Kit of Dynamics Activities (with J. Choate, Key Curriculum Press, 2000) The Mandelbrot and Julia Sets: A Tool Kit of Dynamics Activities (Key Curriculum Press, 2000) Differential Equations (with P. Blanchard and G. R. Hall, 3rd ed., Brooks/Cole, 2005) Differential Equations, Dynamical Systems, and an Introduction to Chaos (with Morris Hirsch and Stephen Smale, 2nd ed., Academic Press, 2004; 3rd ed., Academic Press, 2013)

Research papers Some of the more highly cited of Devaney's research publications include: . . . .