In the 19th century, the Fourier transformation was introduced to study various problems of partial differential equations. Since 1960, this old tool has been developed into a well-organized theory called microlocal analysis that is based on the concept of the pseudo-differential operator. This book explains the origin of the theory.
In the 19th century, the Fourier transformation was introduced to study various problems of partial differential equations. Since 1960, this old tool ...
