arXiv subjects
Publications and source records attributed to Michael R. Pilla.
Recently, a generalization of the Cesàro operator to several variables was introduced as a tuple acting on the Drury-Arveson space \cite{P}. We determine the norm of these Cesàro-type operators and utilize it along with this Cesàro tuple definition to generalize the classical Rhaly operator and recover some basic facts about this operator when applied to the generalization.
The celebrated Cesàro operator is a well-known operator with interesting connections to a variety of objects in operator theory. Generalizations have been made for Cesàro-type operators acting on weighted Hardy spaces but constructing analogs of the Cesàro operator for function spaces of several complex variables such as the Drury-Arveson space has yet to be achieved. In this article, we posit a definition we belief is the correct generalization to several variables and establish a few of its basic properties.
Determining the range of complex maps plays a fundamental role in the study of several complex variables and operator theory. In particular, one is often interested in determining when a given holomorphic function is a self-map of the unit ball. In this paper, we discuss a class of maps in $\mathbb{C}^N$ that generalize linear fractional maps. We then proceed to determine precisely when such a map is a self-map of the unit ball. In particular, we take a novel approach obtaining numerous new results about this class of maps along the way.
For self maps of the disk, it can be shown that under the right conditions one can embed a discrete iteration of the map into a continuous semigroup. In this article we extend these results to two complex variables for maps of the unit ball into itself under some restricted conditions.
In one complex variable, the cross ratio is a well-known quantity associated with four given points in the complex plane that remains invariant under linear fractional maps. In particular, if one knows where three points in the complex plane are mapped under a linear fractional map, one can use this invariance to explicitly determine the map and to show that linear fractional maps are $3$-transitive. In this paper, we define a generalized cross ratio and determine some of its basic properties. In particular, we determine which hypotheses must be made to guarantee that our generalized cross ratio is well defined. We thus obtain a class of maps that obey similar transitivity properties as in one complex dimension, under some more restrictive conditions.