Joseph Fourier
Native spelling: Jean-Baptiste Joseph Fourier
1768–1830, Auxerre, France, Paris, France
French mathematician and physicist who founded the mathematical theory of heat conduction and showed how periodic phenomena can be decomposed into trigonometric waves.
Joseph Fourier was born in Auxerre and studied at the École Normale Supérieure during the French Revolution. He accompanied Napoleon's expedition to Egypt in 1798, later became prefect of Isère, and taught at the École Polytechnique. His study of heat led to the equation now called the heat equation and to the representation of functions by trigonometric series. In his 1807 memoir and 1822 book Théorie analytique de la chaleur, he argued that a broad class of functions can be represented by Fourier series. The convergence and function-space questions behind this claim were developed rigorously by later analysts. The Fourier transform, Fourier analysis, and many methods for partial differential equations now bear his name.
Workplaces: École Polytechnique, University of Grenoble, Institut de France
France