From Wikipedia, the free encyclopedia

Henri Poincaré
PSM V82 D416 Henri Poincare.png
Henri Poincaré
(photograph published in 1913)
Born29 April 1854
Died17 July 1912 (aged 58)
ResidenceFrance
NationalityFrench
Other namesJules Henri Poincaré
EducationLycée Nancy (now Lycée Henri-Poincaré)
Alma mater
Known for
Awards
Scientific career
FieldsMathematics and physics
Institutions
ThesisSur les propriétés des fonctions définies par les équations différences (1879)
Doctoral advisorCharles Hermite
Doctoral students
Other notable students
Influences
Influenced
Signature
Henri Poincaré Signature.svg

Jules Henri Poincaré was a French mathematician, theoretical physicist, engineer, and philosopher of science. He is often described as a polymath, and in mathematics as "The Last Universalist," since he excelled in all fields of the discipline as it existed during his lifetime.

As a mathematician and physicist, he made many original fundamental contributions to pure and applied mathematics, mathematical physics, and celestial mechanics. He was responsible for formulating the Poincaré conjecture, which was one of the most famous unsolved problems in mathematics until it was solved in 2002–2003 by Grigori Perelman. In his research on the three-body problem, Poincaré became the first person to discover a chaotic deterministic system which laid the foundations of modern chaos theory. He is also considered to be one of the founders of the field of topology.

Poincaré made clear the importance of paying attention to the invariance of laws of physics under different transformations, and was the first to present the Lorentz transformations in their modern symmetrical form. Poincaré discovered the remaining relativistic velocity transformations and recorded them in a letter to Hendrik Lorentz in 1905. Thus he obtained perfect invariance of all of Maxwell's equations, an important step in the formulation of the theory of special relativity. In 1905, Poincaré first proposed gravitational waves (ondes gravifiques) emanating from a body and propagating at the speed of light as being required by the Lorentz transformations.

The Poincaré group used in physics and mathematics was named after him.

Life