Ralph Tyrrell Rockafellar (born February 10, 1935) is an American mathematician and one of the leading scholars in optimization theory and related fields of analysis and combinatorics.

He is the author of four major books including the landmark text "Convex Analysis" (1970),[1] which has been cited more than 27,000 times according to Google Scholar and remains the standard reference on the subject, and "Variational Analysis" (1998, with Roger J-B Wets) for which the authors received the Frederick W. Lanchester Prize from the Institute for Operations Research and the Management Sciences (INFORMS).

Formally under the guidance of Professor Garrett Birkhoff, Rockafellar completed his Doctor of Philosophy degree in mathematics from Harvard University in 1963 with the dissertation "Convex Functions and Dual Extremum Problems."

[5] The dissertation was inspired by the duality theory of linear programming developed by John von Neumann, which Rockafellar learned about through volumes of recent papers compiled by Albert W. Tucker at Princeton University.

Rockafellar received the Dantzig Prize from the Society for Industrial and Applied Mathematics (SIAM) and the Mathematical Optimization Society in 1982, delivered the 1992 John von Neumann Lecture, received with Roger J-B Wets the Frederick W. Lanchester Prize from the Institute for Operations Research and the Management Sciences (INFORMS) in 1998 for the book "Variational Analysis."

[8] Rockafellar's research is motivated by the goal of organizing mathematical ideas and concepts into robust frameworks that yield new insights and relations.

In particular, the text dispenses of differentiability as a necessary property in many areas of analysis and embraces nonsmoothness, set-valuedness, and extended real-valuedness, while still developing far-reaching calculus rules.

This includes examining the mathematical properties of risk measures and coining the terms "conditional value-at-risk", in 2000 as well as "superquantile" and "buffered failure probability" in 2010, which either coincide with or are closely related to expected shortfall.