What Greek mathematician who spend most of his professional life in Germany lends his name to the Vitali–Carathéodory theorem?
Constantin Carathéodory Constantin Carathéodory (Greek: Κωνσταντίνος Καραθεοδωρή "Konstantinos Karatheodori"; 13 September 1873 – 2 February 1950) was a Greek mathematician who spent most of his professional career in Germany. He made significant contributions to the theory of functions of a real variable, the calculus of variations, and measure theory. His work also includes important results in conformal representations and in the theory of boundary correspondence. In 1909, Carathéodory pioneered the "Axiomatic Formulation of Thermodynamics" along a purely geometrical approach.
Pierre de Fermat Pierre de Fermat (] ; (Between 31 October and 6 December 1607 – 12 January 1665) was a French lawyer at the "Parlement" of Toulouse, France, and a mathematician who is given credit for early developments that led to infinitesimal calculus, including his technique of adequality. In particular, he is recognized for his discovery of an original method of finding the greatest and the smallest ordinates of curved lines, which is analogous to that of differential calculus, then unknown, and his research into number theory. He made notable contributions to analytic geometry, probability, and optics. He is best known for his Fermat's principle for light propagation and his Fermat's Last Theorem in number theory, which he described in a note at the margin of a copy of Diophantus' "Arithmetica".