Carlo Severini (10 March 1872 – 11 May 1951) was an Italian mathematician: he was born in Arcevia (Province of Ancona) and died in Pesaro.
He graduated in Mathematics from the University of Bologna on November 30, 1897:[1][2] the title of his "Laurea" thesis was "Sulla rappresentazione analitica delle funzioni arbitrarie di variabili reali".
[3] After obtaining his degree, he worked in Bologna as an assistant to the chair of Salvatore Pincherle until 1900.
[4] From 1900 to 1906, he was a senior high school teacher, first teaching in the Institute of Technology of La Spezia and then in the lyceums of Foggia and of Turin;[5] then, in 1906 he became full professor of Infinitesimal Calculus at the University of Catania.
[5] He authored more than 60 papers, mainly in the areas of real analysis, approximation theory and partial differential equations, according to Tricomi (1962).
has Lipschitz continuous first order partial derivatives,[10] jointly with the obvious requirement that the set