Reciprocal property in the unresolved weighted Bergman parameter range

Determine whether every holomorphic function f in the weighted Bergman space A_\alpha^p(\mathbb B_n) satisfying \inf_{z\in\mathbb B_n}|f(z)|>0 also has reciprocal 1/f\in A_\alpha^p(\mathbb B_n) for parameters -n-1<\alpha\leq-p-1.

Background

The paper studies whether a function in a weighted Bergman space whose modulus is bounded below has a reciprocal in the same space. It establishes the reciprocal property for \alpha>-p-1 and for \alpha<-n-1, and treats the endpoint \alpha=-n-1 under additional critical embedding assumptions. After these results, the authors identify the remaining range -n-1<\alpha\leq-p-1 as unresolved.

Resolving this range requires controlling the lower-order products that occur in the higher-order radial derivative formula for Rm(1/f). The authors explain that these cases are related to endpoint embedding problems for analytic Besov spaces and are not settled by the methods developed in the paper.

References

The unresolved parameter range is

-n-1<\alpha\leq-p-1.

— The Reciprocal Problem on Weighted Bergman Spaces  (2609.19896 - Cao et al., 17 Sep 2026) in Section 3, immediately before Section 4