The description of weakly invertible elements of particular function spaces is closely related to a broad range of (sometimes central) problems in several areas, from differential operators and their generalizations to abstract harmonic analysis [1], [2]. In the one-dimensional case the investigation of weakly invertible elements was initiated by Keldysh [3] and has been continued by many authors; see [4]–[9] for details. In the multidimensional case the weak invertibility of bounded analytic functions was considered in [9] for anisotropic weighted function spaces on a polydisc.
展开▼
