1768-1830. French applied mathematician whose
formulation of heat flow 1807 contains the
proposal that, with certain constraints, any
mathematical function can be represented by
trigonometrical series. This principle forms
the basis of Fourier analysis, used today in
many different fields of physics. His idea,
not immediately well received, gained
currency and is embodied in his Theorie
analytique de la chaleur/The Analytical
Theory of Heat 1822.