15/06/27 18:30:17.21 OGuofPc2.net
へへ、英文だと違うね
URLﾘﾝｸ(en.wikipedia.org)
For Riemann?Hilbert factorization problems on the complex plane see Riemann?Hilbert.
The twenty-first problem of the 23 Hilbert problems, from the celebrated list put forth in 1900 by David Hilbert, concerns the existence of a certain class of linear differential equations with specified singular points and monodromic group.
History
This problem is more commonly called the Riemann?Hilbert problem.
There is now a modern (D-module and derived category) version, the 'Riemann?Hilbert correspondence' in all dimensions.
The history of proofs involving a single complex variable is complicated. Josip Plemelj published a solution in 1908.
This work was for a long time accepted as a definitive solution; there was work of G. D. Birkhoff in 1913 also,
but the whole area, including work of Ludwig Schlesinger on isomonodromic deformations that would much later be revived in connection with soliton theory, went out of fashion.
Plemelj (1964) wrote a monograph summing up his work.
A few years later the Soviet mathematician Yuliy S. Il'yashenko and other