Dear all, We have a special talk on Tuesday, December 15 at 10AM CDT (please note the unusual day and time). The talk is a tribute to the greatest Jean Bourgain who passed away almost 2 years ago on December 22, 2018. Please join us at https://unt.zoom.us/j/512907580 Speaker: Keith Ball, University of Warwick Title: Restricted Invertibility Abstract: I will briefly discuss the Kadison-Singer problem and then explain a beautiful argument of Bourgain and Tzafriri that I will include in a forthcoming article in a volume dedicated to Jean Bourgain. For more information about the past and future talks, and videos please visit the webinar website http://www.math.unt.edu/~bunyamin/banach Thank you, and best regards, Bunyamin Sari