Mathematician:Augustin Louis Cauchy


 * French Engineer and mathematician, from a suburb of Paris, which at the time was home to many leading mathematicians.
 * Wrote seven books and more than 700 papers in various fields of mathematics.
 * Made contributions in theory of determinants, eigenvalues, ordinary and partial differential equations, permutation groups, and the foundation of calculus.
 * Famous for founding the theory of functions of a complex variable.
 * Argued by some as the founder of group theory.
 * Cauchy was a devout Roman Catholic, also strongly devoted to the Bourbon kings who ruled France after Napoleon's defeat. When Charles X was exiled in 1830, Cauchy willingly followed the former king into exile in Prague.

Nationality
French

History

 * Born: 21 Aug 1789, Paris, France
 * 1805: Entered the École Polytechnique
 * 1807: Graduated from the École Polytechnique, entered the École des Ponts et Chaussées
 * 1810: Moved to Cherbourg: worked on port facilities for Napoleon's English invasion fleet
 * 1811: Proved that the angles of a convex polyhedron are determined by its faces
 * September 1812: Returned to Paris suffering from depression
 * 1815: Appointed assistant professor of analysis at the École Polytechnique
 * 1816: Won the Grand Prix of the French Academy of Sciences for a work on waves
 * 1817: Replaced Biot at the Collège de France
 * September 1830: Left Paris after the July revolution, and spent a short time in Switzerland where he helped to set up the Académie Helvétique
 * 1831: Went to Turin, accepted an offer from the King of Piedmont of a chair of theoretical physics, where he taught from 1832
 * 1833: To Prague, in order to follow Charles X and to tutor his grandson (with not much success)
 * 1838: Returned to Paris and regained his position at the Academy, but not his teaching positions because he had refused to take an oath of allegiance
 * 1848: Regained his university positions on overthrow of Louis Philippe
 * Died: 23 May 1857, Sceaux (near Paris), France

Theorems and Definitions

 * Binet-Cauchy Identity (with Jacques Philippe Marie Binet) (also known as Binet's Formula)
 * Cauchy Argument Principle
 * Cauchy-Binet Formula (with Jacques Philippe Marie Binet)
 * Cauchy Boundary Condition
 * Cauchy's Convergence Test
 * Cauchy Criterion
 * Cauchy Determinant
 * Cauchy Distribution
 * Cauchy's Equation
 * Cauchy Equivalent
 * Cauchy-Euler Equation (with Leonhard Paul Euler)
 * Cauchy Functional Equation


 * Cauchy-Green Tensor (with George Green)
 * Cauchy's Group Theorem
 * Cauchy Horizon
 * Cauchy Integral Theorem
 * Cauchy's Integral Formula
 * Cauchy Formula for Repeated Integration
 * Cauchy-Frobenius Lemma (with Ferdinand Georg Frobenius)
 * Cauchy-Hadamard Theorem (with Jacques Salomon Hadamard)
 * Cauchy-Kovalevskaya Theorem (with Sofia Kovalevskaya)
 * Cauchy-Lipschitz Theorem (with Rudolf Lipschitz)
 * Cauchy Matrix
 * Cauchy's Mean Theorem (also known as Cauchy's Formula)
 * Cauchy Mean Value Theorem
 * Cauchy Momentum Equation
 * Cauchy-Peano Theorem (with Giuseppe Peano)
 * Cauchy Principal Value
 * Cauchy Problem
 * Cauchy Product
 * Cauchy's Radical Test
 * Cauchy-Riemann Equations (with Bernhard Riemann)
 * Cauchy-Bunyakovsky-Schwarz Inequality (with Viktor Yakovlevich Bunyakovsky and Hermann Amandus Schwarz)
 * Cauchy Sequence
 * Cauchy Surface
 * Cauchy's Theorem (Geometry)
 * Maclaurin-Cauchy Test (with Colin Maclaurin)


 * An elegant proof of what is now called the Nyquist Stability Criterion.

Books and Papers

 * 1821: Cours d'analyse (Course in Analysis)
 * 1823: Le Calcul infinitésimal
 * 1826: Sur un nouveau genre de calcul analogue au calcul infinitésimal
 * 1829: Leçons sur le Calcul Différentiel
 * 1840-47: Exercices d'analyse et de physique mathématique

Also see

 * : Chapter $\text{XV}$
 * : $\S 1.1$
 * : $\S 55$
 * : Chapter $\text{A}.26$