# Henri Poincare : biography

In 1903 Poincare became one of the three members of group of experts who examined the evidence of the “Dreyfus affair”. On the ground of the conclusion that was made by the three experts unanimously, the court brought in a verdict of not guilty.

The main sphere of interest of Poincare in the 20th century was physics, especially electromagnetism and philosophy of science. Poincare showed his deep understanding of the electromagnetic theory; his acute commentaries were highly appreciated and taken into account by Lorentz and other physicists. Since 1890 Poincare started to publish his series of articles and Maxwell’s theory and since 11902 he began to lecture his course about electromagnetism and radio communication. In his article of 1904 and 1905 Poincare passed far ahead of Lorentz in understanding the situation, practically he created the mathematic basis of the relative theory (the physical fundament of the theory was created by Einstein in 1905).

In 1906 Poincare was elected to be the president of Paris Academy oа Science. In 1908 he had a serious disease and was not able to present his report “Future of mathematics” himself at the fourth mathematicians’ congress. The first operation had successful results but four years later Poincare’s state of health worsened again. He died in Paris after an operation on 17 July 1912. Embolism was the reason of his death on the 58th year of his life. The scientist was buried in the family vault at Montparnasse cemetery.

## Contribution to science

The mathematical activity of Poincare was mostly interdisciplinary. Thanks to that fact during the thirty years period of his intensive creative activity hу left fundamental works in almost all spheres of mathematics. Poincare’s works, published by Paris Academy since 1916 till 1956, made eleven volumes in total. Those books were works in such spheres as topology, automorphic functions, theory of differential equations, integral equations, non-Euclidean geometry, and the relative theory, the theory of numbers, celestial mechanics, physics, and philosophy of mathematics and philosophy of science.

In all of the various spheres oа his activity, Poincare managed to get important and profound results. However, there were a lot of scientific works of pure mathematics in his scientific heritage. Those were works in such spheres as abstract algebra, algebraic geometry, theory of numbers and others. In addition to that, among all the works made by Poincare, the ones with direct applied use prevailed over the others. The tendency was clearly since in the period of the last fifteen-twenty years of his activity. However Poincare’s discoveries had quite general character and were successfully used later in other disciplines of science.

The creative method of Poincare was based on inventing an intuitive model of the problem to solve. The scientists almost solved them in his mind firstly and only after that he wrote down the results. Poincare had phenomenal memory and was able to quote word by word the books he read and the conversations he was involved in. the features of Poincare’s memory, intuition and imagination even became the objects of psychological research. Besides that, he never worked at one problem for a long period of time, thinking that the subconsciousness had already got the task and kept working at the problem even while he was thinking about something else. His creative method was described by the scientist in his report “Mathematical creativity” (Paris scientific society, 1908).

## Factor of automorphy

During the whole nineteenth century, almost all of the leading mathematicians took part at working at the theory of elliptical functions, which appeared to be very useful in solving differential equations. But, however those functions didn’t live up the expectations of scientists fully and many mathematicians started to speculate whether it was possible to widen the class of elliptical functions, so that the new functions would be suitable for the equation which were not helped with the elliptical functions.