Bachelier, Louis

(b. Le Havre, France, 11 March 1870; d. Saint-Servan-sur-Mer, Ille-et-Villaine France, 28 April (1946)

mathematics.

Bachelier obtained the bachelor of sciences degree in 1898, and two years later he defended his doctoral dissertation on the theory of speculation. Encouraged by Henri Poincaré, he published three memoirs on probability: “Théorie mathématique des jeux” (1901), “Probailités à plusieurs variables” (1910), and “Probabilités cinématiques et dynamiques” (1913). After being named lecturer at Besançon 1919, he taught at Dijon and Rennes before returning to Besauçon as professor from 1927 to 1937, when he retired.

Under the name “théorie de la spéculation” Bachelier introduced continuity into problems of probability. Making time the variables, he considered the movements of probabilities and chains of probabilities, then applied these ideas to the fluctuations of market rates and to the propagation of light and radiance. The relation between haphazard movement theory of Brownian movement, a classic thory known today as the Einstein-Wiener theory; Wiener’s rigorous study was made in 1928. Bachelier was the first to examine the stochastic methods of the Markovian type, on which A. N. Kolmogorov’s theory is based. Yet lack of clarity and precision, certain considerations of doubtful interest, and some errors in definition explain why, in spite of their originality, his studies exerted no real scientific influence.

Bachelier participated in the diffusion of probabilistic thought through his articles “La périodicité du hasard” and “Quelques curiosités paradoxales du calcul des probabilités” and the book Le Jeu, la chance et le hasard.

BIBLIOGRAPHY

Bachelier’s writings include “Théorie de la spéculation,” in Annales de l’École normale supérieure, 3rd ser., 17 (1900), 21–86; “Théorie mathématique des jeux,” ibid., 18 (1901), 143–210;: Théorie des probabilites continues,” in Journal de mathématiques pures et appliqées, 6th ser., 2, pt. 3 (1906), 259–327; “Probabilitiés á plusieurs variables,” in Annales de l’École normale supérieure, 3rd ser., 27 (1910), 340–360; “Mouvement d’un point ou d’un systéme soumis à l’action de forces dèpendant du hasard,” in Comptes rendus de l’Académie des sciences, 151 (1910), 852–855; Calcul des probabilités (Paris, 1912); “Probabilités cinématiques et dynamiques,” in Annales de l’École normale supérieure, 3rd ser., 30 (1913), 77–119; Le jeu, la chance et le hasard (Paris, 1924); Les lois du grand nombre du calcul des probabilitiés (Paris, 1924); La spéculation et le calcul des probabilitiés (Paris, 1938); and Les nouvelles méthodes du calcul des probabilités (Paris, 1939).

Lucienne FÉlix