The University at Buffalo Department of Mathematics is pleased to announce that the American Mathematical Society has named Professor Hangfeng Li a member of the 2021 Class of Fellows. The international honor places Professor Li among the world's outstanding mathematicians for his contributions to algebraic dynamics and operator algebras. He joined UB Mathematics in 2005, and is currently teaching MTH 424/524, “Survey of Fourier Series Methods”. His main research interest is on noncommutative geometry and dynamical systems, especially connections between operator algebras and dynamical systems. Professor Li's recent work concentrates on actions of countable sofic groups and algebraic actions of general countable (amenable) groups. Read the article by Charlotte Hsu.

Published November 19, 2020

UB mathematician Hanfeng Li has been named a fellow of the American Mathematical Society (AMS) for his contributions to algebraic dynamics and operator algebras.

The fellows program recognizes members from around the world who have made outstanding contributions to the creation, exposition, advancement, communication and utilization of mathematics. Li is among 46 honorees for 2021.

Li is a professor of mathematics in the College of Arts and Sciences. His main research interests are in noncommutative geometry and dynamical systems, especially connections between operator algebras and dynamical systems. Li’s recent work concentrates on actions of countable sofic groups and algebraic actions of general countable (amenable) groups.

Among other past recognitions, Li received a UB Exceptional Scholar Award for Sustained Achievement in 2014.

“Hanfeng Li’s selection in the 2021 class of AMS fellows is a well-deserved recognition for his outstanding work. We are very proud to have him as a colleague,” says Gino Biondini, professor and chair of the Department of Mathematics.

The AMS is dedicated to advancing research and connecting the diverse global mathematical community through its publications, meetings and conferences, MathSciNet, professional services, advocacy and awareness programs.

Western New York has a long affiliation with the AMS. The organization’s very first colloquium — at a summer meeting in 1896, two years after the society became a national group — was held in Buffalo.

*The Society's announcement reads, in part:*

Forty-six mathematical scientists from around the world have been named Fellows of the American Mathematical Society (AMS) for 2021, the program's ninth year.

To see the names of individuals who are in this year's class, their institutions and citations, visit the list of 2021 Fellows.

The Fellows of the AMS designation recognizes members who have made outstanding contributions to the creation, exposition, advancement, communication, and utilization of mathematics. The AMS is pleased to present the class of 2021 Fellows who are being recognized by their peers for their contributions to the profession, and also to honor excellence.

"It is a great pleasure to offer my sincere congratulations to the new AMS Fellows, honored for their notable contributions to mathematics and to the profession. We are grateful to the nominators and the members of the selection committee for helping the AMS recognize the achievements of their esteemed colleagues through this fellowship." says AMS President Jill C. Pipher.

The American Mathematical Society is dedicated to advancing research and connecting the diverse global mathematical community through our publications, meetings and conferences, MathSciNet, professional services, advocacy, and awareness programs.

Buffalo has a long affiliation with the AMS. In 1896, the Colloquium of the American Mathematical Society was born in Buffalo, and continues today with the lectures through the years. Learn more.

# Hanfeng Li

## PhD

Professor### Research Interests

Operator algebras, noncommutative geometry, and dynamical systems.

### Education

PhD, University of California, Berkeley

### Research Summary

Operator algebras, noncommutative geometry, and dynamical systems.

Hanfeng Li’s main research interest is on noncommutative geometry and dynamical systems, especially connections between operator algebras and dynamical systems. His recent work concentrates on actions of countable sofic groups and algebraic actions of general countable (amenable) groups.

### Selected Publications

H. Li and B. Liang, " Sofic mean length”, Adv. Math. 353 (2019), 802--858.

H. Li and B. Liang, "Mean dimension, mean rank, and von Neumann-Lueck rank", J. Reine Angew. Math. 739 (2018), 207--240.

N. Chung and H. Li, "Homoclinic groups, IE groups, and expansive algebraic actions", Invent. Math. 199 (2015), no. 3, 805--858.

H. Li and A. Thom, "Entropy, determinants, and L2-torsion", J. Amer. Math. Soc. 27 (2014), no. 1, 239--292.

H. Li, "Sofic mean dimension", Adv. Math. 244 (2013), 570--604.

D. Kerr and H. Li, "Soficity, amenability, and dynamical entropy", Amer. J. Math. 135 (2013), no. 3, 721--761.H. Li, "Compact group automorphisms, addition formulas and Fuglede-Kadison determinants". Ann. of Math. (2) 176 (2012), no. 1, 303--347.

D. Kerr and H. Li, "Entropy and the variational principle for actions of sofic groups", Invent. Math. 186 (2011), no. 3, 501--558.

G. A. Elliott and H. Li, "Morita equivalence of smooth noncommutative tori", Acta Math. 199 (2007), 1--27.

D. Kerr and H. Li, "Independence in topological and C*-dynamics ", Math. Ann. 338 (2007), no. 4, 869--926.

D. Kerr and H. Li, "Dynamical entropy in Banach spaces", Invent. Math. 162 (2005), no. 3, 649--686.

H. Li, "Strong Morita equivalence of higher-dimensional noncommutative tori", J. Reine Angew. Math. 576 (2004), 167--180.