"Universal
Functions"
By
Abstract: Universality is an abstract notion which
relates to various mathematical contexts. Generally speaking, an object is called
universal if, via a countable process, it can approximate every object in some
class. In this talk we will present several examples which show that universal
objects not only exist, but are generic rather than exceptional. Moreover we
will talk about one of the most widely-studied instances of universality: the
case of universal series, where the approximation is obtained by considering
subsequences of partial sums. In particular, we will focus on holomorphic
functions, and harmonic functions of several variables, which possess universal
polynomial expansions.
Date: Wednesday, May
6, 2015
Time: 15.40-16.30
Place: Mathematics Seminar Room,
SA-141
All are most cordially invited.
Tea and biscuits: after the seminar