Famous figures
Portraits of famous mathematicians, historical and contemporary
A distribution like no other
Standard probability distributions can sometimes be far removed from what is observed. When extreme cases occur too often, the Cauchy distribution comes into its own.
The battle over infinity: Cauchy and limits | Tangente
For more than two centuries, scholars and mathematicians debated infinitesimals: could they be handled safely, or were the paradoxes they generated insoluble? Amid this debate, Cauchy ushered analysis into the modern era while maintaining a nuanced position.
Geometry and philology: Cauchy's limits | Tangente
The mathematician Olry Terquem's review of Cauchy's paper on polyhedra ends in a most curious fashion.
Cauchy: Conviction, maths and politics | Tangente
Cauchy's century was a veritable political laboratory: France passed through a succession of radically different regimes. Amid this constant change, Cauchy, a Legitimist, showed no lack of courage in defending his beliefs. Yet he remained steadfastly devoted to science, even when it meant helping regimes for which he had little sympathy.
Cauchy and his rivals: a man of controversy | Tangente
Disputes over the authorship of theorems reflect the bitter controversies that pitted Cauchy against some mathematicians of his time.
The origins of complex analysis
Cauchy is often credited with single-handedly founding complex analysis. The reality is subtler: although Cauchy gave the subject its structure and rigor, he drew on a wealth of earlier research, notably dating back to d’Alembert. Moreover, his involvement was prompted by debates between Laplace and Poisson over whether the use of complex numbers in integral calculations was legitimate. To understand Cauchy’s work, then, we must reconstruct its entire intellectual context.
A train of thought
It took mathematicians a long time to define a convergent sequence without falling into the many logical traps involved. Cauchy's research was among the most important contributions that eventually clarified the matter.
From Arcueil to Sceaux: in Cauchy's footsteps | Tangente
Cauchy had close ties to the southern suburbs of Paris. After growing up in Arcueil, he spent his holidays in Sceaux, where he produced some of his mathematical work. He also died and was buried there.
Cauchy the poet: defending maths in verse | Tangente
Although his name means only one thing to us—that of a mathematician—Cauchy also had a solid classical education. Having won distinction in the literary papers of the Concours général, he even tried his hand at poetry to explain the value of his science.
The other bicentenary: Cauchy commemorated in 1989 | Tangente
In France, 1989 was a year of major celebrations marking the bicentenary of the 1789 Revolution. Yet it was also the bicentenary of Cauchy's birth.
A series of errors
Nobody is perfect—not even the greatest mathematicians in their own field. Take Cauchy, who made a mistake concerning the convergence of series of functions—one that no student would dare make today.
Worth reading: Belhoste's biography of Cauchy | Tangente
Writing a biography of a man like Cauchy is a tour de force.
Secrets from mathematical archives | Tangente
For its YouTube channel, the Académie des sciences produced a series entitled "Treasures from the archives." Each episode, lasting around five minutes, features a member of the Academy presenting a document from its archives.
Markov recommends Avenue Henri-Martin
The well-known board game Monopoly is a fine example of a stochastic process—a situation whose evolution is governed by the laws of probability. So, to find out whether you should buy Gare Saint-Lazare or Rue de Vaugirard, follow the guide…
A (good) Babylonian approximation
The Babylonians have always been renowned as brilliant mathematicians, and the clay tablets that have survived sometimes bear dazzling witness to their skill.
Marcia Ascher, pioneer | Tangente
Behind a wealth of research in ethnomathematics, mathematician Maria Ascher is regarded as one of the founders of this new discipline
Laurent Schwartz, politically engaged mathematician | Tangente
The publication of the graphic novel Laurent Schwartz, les engagements d'un médaillé Fields offers an opportunity to revisit the life and struggles of this surprising mathematician.
Fermat Museum: Heritage and mathematics | Tangente
In July 2024, the Fermat Museum opened in Pierre de Fermat's birthplace in Beaumont-de-Lomagne, Tarn-et-Garonne.
The new Fourier has arrived! | Tangente
The mathematician Joseph Fourier is buried in Père-Lachaise Cemetery (Division 18, near the Casimir-Perrier roundabout) in Paris. His tomb, decorated with Egyptian motifs, was restored in 2023 by the City of Paris at the request of the Society of Friends of Joseph Fourier.
Beyond Gauss in finance | Tangente
Gaussian curves are unsuitable for modelling risky financial assets such as stocks. To overcome this problem, Benoît Mandelbrot introduced the concept of a multifractal measure and generalized Brownian motion.