Pierre-Louis de Maupertuis introduced the concept of the calculus of variations in his 1744 work, "Essai de cosmologie."

Thomas Bayes is renowned for his contributions to probability theory, particularly Bayes' theorem, which provides a method for updating beliefs in light of new evidence.

Leonhard Euler derived the Euler-Lagrange equation, a fundamental equation in the calculus of variations, in his 1744 work, "Methodus inveniendi lineas curvas maximi minimive proprietate gaudentes."

Carl Friedrich Gauss made significant contributions to number theory, including his work on prime numbers and the distribution of primes.

Pierre-Simon Laplace introduced the Laplace transform, a mathematical tool used to solve differential equations, in his 1785 work, "Théorie analytique des probabilités."

Charles-Augustin de Coulomb made significant contributions to the theory of elasticity, particularly in his study of the torsion of wires.

Abraham de Moivre introduced the concept of the generating function in his 1730 work, "Miscellanea Analytica."

Jean le Rond d'Alembert made significant contributions to the theory of differential equations, including his work on the wave equation.

Jean-Baptiste Joseph Fourier introduced the Fourier series, a mathematical tool used to represent periodic functions, in his 1822 work, "Théorie analytique de la chaleur."

Caspar Wessel made significant contributions to the theory of complex numbers, including his work on the geometric representation of complex numbers.

Adrien-Marie Legendre introduced the method of least squares, a statistical method used to find the best-fit line or curve to a set of data, in his 1805 work, "Nouvelles méthodes pour la détermination des orbites des comètes."

Pierre-Simon Laplace made significant contributions to the theory of determinants, including his work on the Laplace expansion.

Augustin-Louis Cauchy introduced the Cauchy-Riemann equations, a system of partial differential equations that characterize holomorphic functions, in his 1825 work, "Mémoire sur les intégrales définies."

Évariste Galois made significant contributions to the theory of groups, including his work on the Galois group of a polynomial.

Bernhard Riemann introduced the Riemann zeta function, a function of a complex variable that has applications in number theory and other areas of mathematics, in his 1859 paper, "Über die Anzahl der Primzahlen unter einer gegebenen Grösse."