Pointwise multipliers from the Hardy space to the Bergman space
Feldman, Nathan S.
Illinois J. Math., Tome 43 (1999) no. 3, p. 211-221 / Harvested from Project Euclid
For which regions $G$ is the Hardy space $H^{2}(G)$ contained in the Bergman space $L^{2}_{a}(G)$? This paper relates the above problem to that of finding the multipliers of $H^{2}(\mathbb{D})$ into $L^{2}_{a}(\mathbb{D})$. When $G$ is a simply connected region this leads to a solution of the above problem in terms of Lipschitz conditions on the Riemann map of $\mathbb{D}$ onto $G$. For arbitrary regions $G$, it is shown that if $G$ is the range of a function whose derivative is a multiplier from $H^{2}(\mathbb{D})$ to $L^{2}_{a}(\mathbb{D})$, then $H^{2}(G)$ is contained in $L^{2}_{a}(G)$. Also, if $G$ has a piecewise smooth boundary, then it is shown that $H^{2}(G)$ is contained in $L^{2}_{a}(G)$ if and only if the angles at all the “corner” points are at least $\pi/2$. Examples of multipliers from $H^{2}(\mathbb{D})$ to $L^{2}_{a}(\mathbb{D})$ are given; and in particular, every Bergman inner function is such a multiplier.
Publié le : 1999-06-15
Classification:  46E15,  30H05
@article{1255985210,
     author = {Feldman, Nathan S.},
     title = {Pointwise multipliers from the Hardy space to the Bergman space},
     journal = {Illinois J. Math.},
     volume = {43},
     number = {3},
     year = {1999},
     pages = { 211-221},
     language = {en},
     url = {http://dml.mathdoc.fr/item/1255985210}
}
Feldman, Nathan S. Pointwise multipliers from the Hardy space to the Bergman space. Illinois J. Math., Tome 43 (1999) no. 3, pp.  211-221. http://gdmltest.u-ga.fr/item/1255985210/