Professor Maria J. Esteban is a Basque-French mathematician. In her research, she studies nonlinear partial differential equations, mainly by the use of variational methods, with applications to physics and quantum chemistry. She has also worked on fluid-structure interaction. She did her PhD thesis at the Pierre and Marie Curie University (Paris), under the direction of Pierre-Louis Lions. After graduation, she became full-time researcher at CNRS, where she holds now a position of director of research. From 2015 to 2019, she is president of International Council for Industrial and Applied Mathematics (ICIAM). She was president of the Société de Mathématiques Appliquées et Industrielles from 2009 to 2012 and chair of the Applied Mathematics Committee of the European Mathematical Society in 2012 and 2013. She participated in the Forward Look on "Mathematics and Industry" funded by the European Science Foundation and is one of the launchers of the EU-MATHS-IN European network for industrial mathematics.

TITLE: Rigidity, nonlinear flows and optimal symmetry for extremals of functional inequalities.

ABSTRACT

The analysis of optimality and symmetry properties of extremals in functional inequalities has been performed recently by introducing nonlinear flows into the picture. These results solve conjectures about symmetry and symmetry breaking in functional inequalities which play an important role in various areas of analysis. Also, as a consequence we have obtained optimal estimates for the principal eigenvalues of linear operators and rigidity results of solutions of nonlinear elliptic PDEs for compact and noncompact in Riemaniann manifolds.

Raymond Chan graduated with First Class Honors from the Department of Mathematics at The Chinese University of Hong Kong in 1980. Uncertain of what to do next, he stayed in the Department as a full-time lecturer after graduation. He started his graduate study in 1981 with a full fellowship from the Courant Institute of Mathematical Sciences at New York University. He obtained his M.Sc. and Ph.D. degrees in Applied Mathematics there in 1984 and 1985 respectively under the supervision of Professor Olof Widlund.

Chan began his career as a tenure-track Assistant Professor at the University of Massachusetts at Amherst in 1985. With heart and mind always in Hong Kong, he came back to Hong Kong in 1986, first at The University of Hong Kong (1986-92) and then at The Hong Kong University of Science and Technology (1993) before joining his Alma Mater in 1993. He was the Associate Director of the Institute of Mathematical Sciences (1996-98), the Associate Dean of Science (2004-2009) and now the Head of the Mathematics Department since 2012.

Chan has published 130 journal papers and has been in the ISI Science Citation List Top 250 Highly-Cited Mathematicians in the world since 2004. He won a Leslie Fox Prize for Numerical Analysis in 1989 at Cambridge, United Kingdom; a Feng Kang Prize of Scientific Computing in 1997 in Beijing, China; a Morningside Award in 1998 in Beijing, China; and 2011 Higher Education Outstanding Scientific Research Output Awards (First Prize) from the Ministry of Education in China. He was elected a SIAM Fellow in 2013 and a SIAM Council Member for 2015-17.

Chan has served on the editorial boards of many journals, including: Asian Journal of Mathematics (co-Chief Editor since 1997), Advances in Computational Mathematics (since 2010),Journal of Mathematical Imaging and Vision (since 2014), Journal of Scientific Computing (since 2013), Numerical Linear Algebra with Applications (since 2004), SIAM Journal on Imaging Sciences (since 2007), and SIAM Journal on Scientific Computing (served from 2000 to 2008). He presented over 150 invited conference talks in more than 20 countries, including plenary talks at SIAM Conference on Applied Linear Algebra and SIAM Conference on Imaging Science. He also reviewed papers for more than 110 different journals.

His wonderful group of graduate students includes: Xiaoqing Jin, the Vice-President of East Asia SIAM and former Head of the Mathematics Department at Macau University; Michael Ng, Head of Department of Mathematics at the Hong Kong Baptist University; Wai-Ki Ching, Head of Department of Mathematics at University of Hong Kong; Hao-Min Zhou, an NSF CAREERawardee in 2007; Zheng-Jian Bai, the first prize winner of Applied Numerical Algebra Prize in 2008; and Xiaohao Cai, the first prize winner of EASIAM Student Paper Prize in 2013.

Title: Point-spread function reconstruction in ground-based astronomy

Abstract 

Because of atmospheric turbulence, images of objects in outer space acquired via ground-based telescopes are usually blurry. One way to estimate the blurring kernel or point spread function (PSF) is to make use of the aberration of wavefront received at the telescope, i.e., the phase. However only the low-resolution wavefront gradients can be collected by wavefront sensors. In this talk, I will discuss how to use regularization methods to reconstruct high-resolution phase gradients and then use them to recover the phase and the PSF in high accuracy.