NOVEMBER 23, 2023

SPEAKER:   Raphaël Clouâtre,  Associate Professor, University of Manitoba

(Learn more about the speaker here)

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TITLE:   "Pure States on Operator Algebras"

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ABSTRACT:  Let B be a normed space and let A be a subspace. When does a continuous linear functional on A admit a unique norm-preserving extension to B? If A and B are C*-algebras and the functional is a so-called pure state, this question was at the heart of a long-standing conjecture of Kadison and Singer from 1959, which was eventually verified in 2015 by Marcus, Spielman and Srivastava. In this talk I will explore the corresponding problem for pure states on subspaces of C*-algebras. I will explain how this is non-trivial even for familiar choices of B, such as the continuous functions on some compact space, or the n x n matrices. I will attempt to clarify this issue using a non-commutative counterpart to the classical notion of peak point from function theory. 

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TIME:  All in the Central Time Zone

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Meet and Greet:

• 2:00pm-2:30pm CST

​Talk:

• 2:30pm-3:20pm CST 

Questions:

• 3:20pm-3:30pm CST

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LOCATION:

The event will take place via Zoom.

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ZOOM LINK: https://usask-ca.zoom.us/j/96349416490?pwd=MTg2dDZZNXdOMlJESEs2Ly9WL1ZoZz09

Meeting ID: 963 4941 6490

 

Passcode: 64909186

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