John Forbes Nash Jr., 1928–2015, was a trailblazing American mathematician whose pioneering work greatly advanced differential geometry and partial differential equations. He received a number of awards in recognition of his contribution to mathematics, the most prominent being the Nobel Prize in Economics and the Abel Prize, both in 1994 and 2015 respectively.

Nash is credited with numerous mathematical developments, particularly the Nash Embedding Theorem, which demonstrated that every Riemannian manifold of non-positive curvature can be isometrically embedded in Euclidean space. This radically improved the concepts of proximity, topology and shape, and opened up the possibility of studying them mathematically. It also opened the way for the development of computer science, which applies geometry in an entirely different way than traditional mathematics, by simulating physical phenomena.

The Nobel Prize in Economics honored Nash's work in game theory, a field of mathematics related to decision making and its consequences. His work in this field contributed to understanding of interactive decision making when multiple parties are involved.

Nash was a resident of Massachusetts and was on a visit to New Jersey when he died in a car accident in 2015. His death has been mourned around the world and his legacy lives on in the fields of mathematics and game theory.