Marc-Antoine Parseval des Chênes (27 April 1755 – 16 August 1836) was a French

mathematician A mathematician is someone who uses an extensive knowledge of mathematics in their work, typically to solve mathematical problems. Mathematicians are concerned with numbers, data, quantity, mathematical structure, structure, space, Mathematica ...

, most famous for what is now known as

Parseval's theorem In mathematics, Parseval's theorem usually refers to the result that the Fourier transform is unitary; loosely, that the sum (or integral) of the square of a function is equal to the sum (or integral) of the square of its transform. It originates ...

, which showed that the

Fourier transform In mathematics, the Fourier transform (FT) is an integral transform that takes a function as input then outputs another function that describes the extent to which various frequencies are present in the original function. The output of the tr ...

unitary Unitary may refer to: Mathematics * Unitary divisor * Unitary element * Unitary group * Unitary matrix * Unitary morphism * Unitary operator * Unitary transformation * Unitary representation * Unitarity (physics) * ''E''-unitary inverse semigr ...

. He was born in Rosières-aux-Salines,

France France, officially the French Republic, is a country located primarily in Western Europe. Overseas France, Its overseas regions and territories include French Guiana in South America, Saint Pierre and Miquelon in the Atlantic Ocean#North Atlan ...

, into an aristocratic French family, and married Ursule Guerillot in 1795, but divorced her soon after. A monarchist opposed to the French Revolution, imprisoned in 1792, Parseval later fled the country for publishing poetry critical of the government of

Napoleon Napoleon Bonaparte (born Napoleone di Buonaparte; 15 August 1769 – 5 May 1821), later known by his regnal name Napoleon I, was a French general and statesman who rose to prominence during the French Revolution and led Military career ...

. Later, he was nominated to the

French Academy of Sciences The French Academy of Sciences (, ) is a learned society, founded in 1666 by Louis XIV at the suggestion of Jean-Baptiste Colbert, to encourage and protect the spirit of French Scientific method, scientific research. It was at the forefron ...

five times, from 1796 to 1828, but was never elected. His only mathematical publications were apparently five papers, published in 1806 as ''Mémoires présentés à l'Institut des Sciences, Lettres et Arts, par divers savants, et lus dans ses assemblées. Sciences mathématiques et physiques. (Savants étrangers.)'' This combined the following earlier monographs: # "Mémoire sur la résolution des équations aux différences partielles linéaires du second ordre," (5 May 1798). # "Mémoire sur les séries et sur l'intégration complète d'une équation aux différences partielles linéaires du second ordre, à coefficients constants," (5 April 1799). # "Intégration générale et complète des équations de la propagation du son, l'air étant considéré avec ses trois dimensions," (5 July 1801). # "Intégration générale et complète de deux équations importantes dans la mécanique des fluides," (16 August 1803). # "Méthode générale pour sommer, par le moyen des intégrales définies, la suite donnée par le théorème de M. Lagrange, au moyen de laquelle il trouve une valeur qui satisfait à une équation algébrique ou transcendante," (7 May 1804). It was in the second 1799, memoir in which he stated, but did not prove (claiming it to be self-evident), the theorem that now bears his name. He further expanded it upon his 1801 memoir, and used it to solve various differential equations. The theorem was first printed in 1800 as a part (p. 377) of ''Traité des différences et des séries'' by Lacroix.

References

* * {{DEFAULTSORT:Parseval, Marc-Antoine 1755 births 1836 deaths 18th-century French mathematicians 19th-century French mathematicians

See also

References