Abstract
For an open set V subset of C-n, denote by M-alpha(V) the family of a-analytic functions that obey a boundary maximum modulus principle. We prove that, on a bounded "harmonically fat" domain Omega subset of C-n, a function f is an element of M-alpha (Omega\f(-1)(0)) automatically satisfies f is an element of M-alpha(Omega), if it is C alpha j-1-smooth in the z(j) variable, alpha is an element of Z(+)(n) up to the boundary. For a submanifold U subset of C-n, denote by M-alpha(U), the set of functions locally approximable by a-analytic functions where each approximating member and its reciprocal (off the singularities) obey the boundary maximum modulus principle. We prove, that for a C-3-smooth hypersurface, Omega, a member of M-alpha(Omega), cannot have constant modulus near a point where the Levi form has a positive eigenvalue, unless it is there the trace of a polyanalytic function of a simple form. The result can be partially generalized to C-4-smooth submanifolds of higher codimension, at least near points with a Levi cone condition.
Translated title of the contribution | Nivåmängder för vissa klasser av α-analytiska funktioner |
---|---|
Original language | English |
Pages (from-to) | 281-298 |
Journal | Journal of partial differential equations |
Volume | 30 |
Issue number | 4 |
DOIs | |
Publication status | Published - 2017 |
Subject classification (UKÄ)
- Mathematical Analysis
Free keywords
- polyanalytic functions
- q -analytic functions
- zero sets
- level sets
- α -analytic functions