Kohn's Lemma
Kohn's Lemma is a result in complex analysis, particularly in the study of several complex variables. It provides conditions under which a holomorphic function defined on a domain can be approximated by holomorphic functions that are defined on a larger domain. This lemma is particularly useful in understanding the behavior of functions near the boundaries of their domains.
The lemma is named after the mathematician L. Kohn, who contributed significantly to the field of several complex variables. Kohn's Lemma helps in establishing the existence of solutions to certain types of partial differential equations, making it an important tool in both theoretical and applied mathematics.