**The 2019 Cantrell Lecture Speaker will be Professor Geordie Williamson of the University of Sydney. **

Professor Williamson is one of the world's foremost experts in geometric representation theory. His counterexamples to the Lusztig conjecture have led to new and exciting research in the area of modular representation theory, in which he is one of the leaders. Another of his major accomplishments involves joint work with Ben Elias which settled a long-standing conjecture about positivity of Kazhdan-Lusztig polynomials for arbitrary Coxeter groups. Professor Williamson was awarded the Chevalley prize of the AMS (2016), a Clay Research Award (2016), the EMS prize (2016), the New Horizons in Mathematics prize (2017), and was elected a Fellow of the Royal Society (2018).

**Title for all 3 talks: ** *Representation theory and geometry*

**November 12, 2019** - Physics Bldg. Room 202, 3:30pm (Refreshments will be served at 3:00pm outside of Room 202)

**Abstract: **This lecture series will focus on representation theory, from its origins in the study of finite groups by Frobenius in the final years of the 19th century, through to recent problems and questions. A theme throughout is the recurring presence of geometry in what at first appears an algebraic subject. The first lecture will be largely historical, and will provide a potted history of the subject up until the 1970s.

**November 13, 2019 **- Boyd Graduate Studies Research Bldg., Room 328 3:30pm (Refreshments will be served at 3:00pm outside of Room 328)

**Abstract: **This lecture will cover the Kazhdan-Lusztig conjectures, which played an important role in the development of the subject in the last two decades of the 20th century.

**November 14, 2019** - Boyd Graduate Studies Research Bldg., Room 328 3:30pm (Refreshments will be served at 3:00pm outside of Room 328)

**Abstract:** This lecture will focus on modular representation theory, which is still providing us with many interesting mysteries today.

The 2019 Cantrell Lecture Speaker will be Professor Geordie Williamson of the University of Sydney.

Professor Williamson is one of the world's foremost experts in geometric representation theory. His counterexamples to the Lusztig conjecture have led to new and exciting research in the area of modular representation theory, in which he is one of the leaders. Another of his major accomplishments involves joint work with Ben Elias which settled a long-standing conjecture about positivity of Kazhdan-Lusztig polynomials for arbitrary Coxeter groups. Professor Williamson was awarded the Chevalley prize of the AMS (2016), a Clay Research Award (2016), the EMS prize (2016), the New Horizons in Mathematics prize (2017), and was elected a Fellow of the Royal Society (2018).