BERTRAND HAUCHECORNE
179 articles published in Tangente
Math for everyoneN°213Aug 28, 2023Carmichael numbers
Does Fermat's little theorem characterize prime numbers? Far from it! Yet few composite numbers satisfy the theorem's conclusion, making them all the more intriguing to number-theory enthusiasts and specialists alike.
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History and CultureN°213Aug 25, 2023Catalan numbers
Eugène Charles Catalan (1814–1894), the son of a Parisian jeweler, was born in Bruges, Belgium. A brilliant student, he entered the École polytechnique in 1833, where he befriended a teaching assistant who would later become famous: Joseph Liouville.
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Math for everyoneN°87Aug 24, 2023The Cauchy–Schwarz inequality
The Cauchy–Schwarz inequality takes many forms: arithmetic, integral and geometric; it even appears in probability theory. Let us trace its development, from Cauchy's numerical formulation around 1820 to its general form a century later.
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Math for everyoneN°87Aug 24, 2023Five variants of the Cauchy–Schwarz inequality
The Cauchy–Schwarz inequality appears in several branches of mathematics: analysis, arithmetic, geometry, probability... It is so important that many widely differing proofs have been devised!
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History and CultureN°210Feb 22, 2023The triumphs and tribulations of summing a series
Every convergent series can be assigned a sum—but what about divergent series? Mathematical orthodoxy holds that they cannot be assigned a value. Yet Leibniz and Euler suggested a few possible approaches. Poisson, Frobenius and Borel later crossed that forbidden line.
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History and CultureN°85Feb 17, 2023A mind outside the mainstream
Blaise Pascal was no universal scholar, but he developed a rigorous, experiment-based scientific method that enabled him to transcend the prevailing orthodoxy and open up new avenues in both mathematics and physics.
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History and CultureN°209Dec 23, 2022Nalini Anantharaman at the Collège de France
She was among the favorites for a Fields Medal in 2014; now she has been awarded a chair at the Collège de France!
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History and CultureN°209Dec 22, 2022A journey into infinity
While many mathematicians toiled in the footsteps of their predecessors, Cantor opened up an entirely new field that many of his colleagues refused to enter. This journey through the different infinities proved to be both fascinating and fruitful.
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History and CultureN°84Nov 21, 2022The origins of the tangent
“Tangent” is a word that has found its way into everyday language. But where did it come from?
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History and CultureN°208Oct 24, 2022Mathematicians to the last breath!
Mathematical creativity seems to wane with age. Few results of real importance have been proved after the age of 50. Yet some mathematicians defy this prejudice, pursuing fruitful scientific work right up to their last breath. So what is their secret?
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History and CultureN°208Oct 21, 2022Late arrivals to mathematics
Few mathematicians reach their first fundamental results late in life. Yet examples exist, even among the most celebrated scholars. The reasons behind this turn toward the queen of the sciences at a mature age are varied, as shown by the paths of Cardano, Napier and Weierstrass.
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History and CultureN°206Jun 21, 2022A century lived with passion
Bertrand Russell was no ordinary mathematician. His Nobel Prize in Literature attests to the breadth of his talents. His advocacy of sexual freedom and his campaigning for peace gave this exceptional man his full stature.
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