1920-1998

Argentinean engineer and mathematician who made fundamental contributions to mathematical analysis. Along with Antoni Zygmund, Calderón developed the Calderón-Zygmund theory of singular integral operators. Calderón's work provided solutions for elliptic differential operators and, subsequently, pseudodifferential operators. He perfected techniques that became important tools of harmonic, nonlinear, and complex analysis. He also published important results regarding the Cauchy problem involving partial differential equations, the Atiyah-Singer index theorem, and the propagation of singularities in nonlinear equations.