Two world-class scientists at City University of Hong Kong (CityU) have been elected Fellows of the European Academy of Sciences (EurASc) in recognition of their outstanding contributions to the field of mathematics.

The newly elected academicians are Professor Felipe Cucker and Professor Yang Tong, both from CityU’s Department of Mathematics. They both have a long relationship with CityU, having joined the Department of Mathematics in the 1990s.

“It is an honour to be elected. I was surprised because I was not expecting it at all,” said Professor Cucker, whose main research focus is the foundational aspects of numerical algorithms.

Professor Cucker joined CityU 22 years ago and is Chair Professor and Head of Department. One of his most influential works is the Cucker-Smale flocking model, a pioneering mathematical model on how birds adopt a common velocity when flying. It shows that under some conditions that can be expressed in terms of initial velocities and positions this common velocity is eventually reached. The model has received widespread attention from applied mathematics and control engineering communities around the world.

Recent research has included areas such as learning theory and mathematical modelling for the evolution of human language.

Professor Cucker’s passion for mathematics has inspired his students and has greatly contributed to the overall study of mathematics. What’s more, as an avid art lover, he has planted the seeds of mathematics in the creative domain. His course “Art and Mathematics” discusses the mathematical nature of the rules of art such as for the symmetry found in painting and counterpoints in Bach’s music.

Professor Cucker published a book Manifold Mirrors: The Crossing Paths of the Arts and Mathematics in 2013, and in 2016 he paired up with digital artist Dr Hector Rodriguez of the School of Creative Media to create a new media artwork using sets of prints and videos that visualise the mathematical Theory of Approximation. The art work made an impact globally and was exhibited in Europe.

The other new Fellow is Professor Yang Tong, Chair Professor in the Department. Professor Yang works in partial differential equations and kinetic theories. One of his significant contributions lies in the area of hyperbolic conservation laws. In 1999, Professor Yang together with Stanford University’s Professor Liu Taiping constructed the “Liu-Yang functional”, which established the theory and stability of hyperbolic conservation laws in one-dimension. 

“I feel privileged to be part of the Academy. It is great recognition for my work,” he said, noting that he was grateful for CityU’s support. “CityU emphasises research and recognises efforts made, which creates a positive environment.”

Prandtl’s boundary layer theory is Professor Yang’s latest research area. Developed in 1904 and widely applied in physics and engineering in the field of aerodynamics, this important advance in fluid dynamics still lacks a mathematical proof. Professor Yang’s objective is to prove this theory mathematically, and then develop it within a 3D context.

Though mathematics can be expressed in equations and models, the initial research with most mathematics-related topics requires early work to be carried out inside the imaginative minds of the mathematicians themselves. For this practice to be successful, Professor Yang said that mathematicians ought to be focused, independent, and persistent in their area of special interest.

This was echoed by Professor Cucker “You have to be stubborn sometimes to stop yourself from giving up,” he said.

Founded in 2003 and based in Brussels, EurASc promotes excellence in science and technology. Currently the Academy has some 600 members in its nine divisions, including 65 Nobel Prize and Fields Medal winners, from 45 nations.