Departmental PhD Thesis Exam – Mircea Voda

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before the exam.

DEPARTMENTAL PHD THESIS EXAM - Mircea Voda

Thursday, April 21, 2011, 11:10 a.m., in BA 6183

PhD Candidate:  Mircea Voda

PhD Advisor:    Ian Graham

Thesis Title:   Loewner Theory in Several Complex Variables and
Related Problems
(http://individual.utoronto.ca/mvoda/thesis.pdf)

Thesis Abstract:
The first part of the thesis deals with aspects of Loewner theory in several complex variables.
First we show that a Loewner chain with minimal regularity assumptions (Df(0,t) of local bounded
variation) satisfies an associated Loewner equation. Next we give a way of renormalizing a
general Loewner chain so that it corresponds to the same increasing family of domains. To do this
we will prove a generalization of the converse of Caratheodory's kernel convergence theorem.
Next we address the problem of finding a Loewner chain solution to a given Loewner chain equation.
The main result is a complete solution in the case when the infinitesimal generator satisfies
Dh(0,t)=A where inf {Re<Az,z>: ||z| =1}> 0. We will see that the existence of a bounded solution
depends on the real resonances of A, but there always exists a polynomially bounded solution.
Finally we discuss some properties of classes of biholomorphic mappings associated to A-normalized
Loewner chains. In particular we give a characterization of the compactness of the class of spirallike
mappings in terms of the resonance of A.

The second part of the thesis deals with the problem of finding examples of extreme points for some
classes of mappings. We see that straightforward generalizations of one dimensional extreme
functions give examples of extreme Caratheodory mappings and extreme starlike mappings on the
polydisc, but not on the ball. We also find examples of extreme CarathÃ©odory mappings on the ball
starting from a known example of extreme Caratheodory function in higher dimensions.