Hadamard, J. Partielle Differentialgleichungen und reelle Funktionen. (Portuguese) Zbl 0044.09401 Gaz. Mat., Lisboa 12, No. 50, 3-6 (1951). In this short expository paper the author stresses the relationship between real variable theory and partial differential equations with non-analytic Cauchy data. For instance, it is shown how the heat equation leads to the consideration of a certain class of functions which have derivatives of all orders but are not analytic. Reviewer: Mauricio Matos Peixoto Page: −5 −4 −3 −2 −1 ±0 +1 +2 +3 +4 +5 Show Scanned Page MSC: 35A99 General topics in partial differential equations 26A99 Functions of one variable Keywords:partial differential equations; non-analytic Cauchy data; real variable theory PDFBibTeX XMLCite \textit{J. Hadamard}, Gaz. Mat., Lisb. 12, No. 50, 3--6 (1951; Zbl 0044.09401)