Biography
Le Yang or Lo Yang, Chinese mathematician (Nantong, Jiangsu Province 10 November 1939 –
Introduced the concept of deficient functions and proved its countability
With Guanghou Zhang introduced the concept of defects and singularity directions in distribution theory
Obtained the precise estimate of total deficiency for any meromorphic function with its derivative
With G. Zhang first established the numbers of deficient values and Borel directions of entire and meromorphic functions (1970s)
Established new criteria for normality
Established relationship between normal families and fixed points as well as that between normal families and different polynomials
Established the necessary and sufficient conditions for the distribution of singular directions
Found a new kind of singular directions
With W.K. Hayman solved a conjecture of Littlewood
EPONYMY
Le Yang inequality
Yang-Zhang theorem (relation between deficit value and singular directions) 1977
Yang-Zhang inequality
Yang relation of deficiencies
Yang problem in derivative functions with maximal deficiency sum
