Наредни састанак Семинара биће одржан у четвртак, 15. новембра 2018. у сали 301ф Математичког института САНУ са почетком у 17:15.
Предавач: Никола Тунески, Cyril and Methodius University in Skopje, Republic of Macedonia
Наслов предавања: UNIVALENT FUNCTIONS: SHORT INTRODUCTION AND SOME NEW RESULTS
Апстракт:A complex function of one variable is said to be univalent if it is one-on-one and onto. The Riemann mapping theorem gives right to consider only univalent functions defined on the unit disk, while a result of Titchmarsh justifies normalization of univalent functions in a way that f(0) = f'(0) – 1 = 0, i.e., f(z) = z + a2z2 + a3z3 + ….. These functions form the class of univalent functions S. The Bieberbach conjecture from 1916 busted the interest for the class Swhich resulted in development of variety of new methods and delivery of plenty significant results. It was finally proven by de Branges in 1984. Nevertheless, the interest for univalent functions remained. The class S is large and the study is usually focused on its subclasses that carry quite descriptive names such as starlike functions, convex functions, close-to-convex functions, functions with bounded turning etc. There are two major directions for research:
– find sufficient condition that embed certain function in the class of univalent functions or some of its subclasses (the condition is usually over a simple expression involving f, f’, f“ or over the coefficients from the expansion of f);
-study the geometrical and analytical properties of functions in S or its subclasses.
The lecture will give definitions and explanations of the main terms, as well as explanation of the methods that I most frequently use in my research (differential subordinations and Clunie-Jack lemma). The focus will be on presentation of selected results from the theory with highlights of mine contribution.