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2 unusual facts about Poincaré


Brouwer fixed-point theorem

The theorem was first studied in view of work on differential equations by the French mathematicians around Poincaré and Picard.

More than 20 years earlier Henri Poincaré had proved an equivalent result, and 5 years before Brouwer P.


Earth's orbit

Mathematicians and astronomers (such as Laplace, Lagrange, Gauss, Poincaré, Kolmogorov, Vladimir Arnold, and Jürgen Moser) have searched for evidence for the stability of the planetary motions, and this quest led to many mathematical developments, and several successive 'proofs' of stability for the solar system.

Grigori Perelman

In 1999, the Clay Mathematics Institute announced the Millennium Prize Problems: $1,000,000 prizes for the proof of any of seven conjectures, including the Poincaré conjecture.

Homology sphere

In 2003, lack of structure on the largest scales (above 60 degrees) in the cosmic microwave background as observed for one year by the WMAP spacecraft led to the suggestion, by Jean-Pierre Luminet of the Observatoire de Paris and colleagues, that the shape of the Universe is a Poincaré sphere.

Hopf bifurcation

In the mathematical theory of bifurcations, a Hopf or Poincaré–Andronov–Hopf bifurcation, named after Henri Poincaré, Eberhard Hopf, and Aleksandr Andronov, is a local bifurcation in which a fixed point of a dynamical system loses stability as a pair of complex conjugate eigenvalues of the linearization around the fixed point cross the imaginary axis of the complex plane.

Montserrat Teixidor i Bigas

She is the most senior of three Principal Investigators for the Poincaré Institute, which was launched in 2011 with funding from the NSF, which announced : receiving $9,550,799, Tufts University (Medford) for the project, entitled “The Poincare Institute: A Partnership for Mathematics Education,” which is under the direction of Montserrat Teixidor-i-Bigas.

Occupation of the Ruhr

When on 12 July 1922, Germany demanded a moratorium on reparation payments, tension developed between the French government of Raymond Poincaré and the Coalition government of David Lloyd George.

Pierre Lelong

Pierre Lelong (14 March 1912 Paris – 12 October 2011) was a French mathematician who introduced the Poincaré–Lelong equation and the Lelong number.

Poincaré sphere

In condensed matter physics, the Poincaré sphere is also known as the Bloch sphere.

Rufus Bowen

As Poincaré emphasized, there is no general procedure for this, and therefore one must resort to describing average, typical, or most probable behavior.

Sergey Martinson

Martinson's career in film started in 1924, when he played his first role of Poincare in the film of the Adventures of Oktyabrina.


see also