主讲人：冯自勤（University of Birmingham）

时  间：6月11日（周二）15：00-16：30

地  点：威尼斯欢乐娱人城1099北二区教学楼 130 教室

备  注：Abstract: The 13th Problem from Hilbert's famous list asks: can every continuous function of three variables be written as a composition of functions of two variables? Hilbert expected the answer to be ‘no’. In 1954 Vitushkin proved that there are continuously differentiable functions of 3 variables which can not be written as a composition of continuously differentiable functions of 2 variables. Thereby giving the kind of negative result Hilbert was expecting. But three years later Kolmogorov gave a remarkable positive solution - in fact every continuous function of n variables can be written as a composition of functions of just one variable plus addition. In this talk I will outline the work of the speaker and Dr. Paul Gartside surrounding Hilbert’s 13th Problem and its connections to various aspects of topology, including dimension theory, small cardinals, and PCF theory, along with its application to approximation theory and universal PDEs.