# Operator Algebras Seminar

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Fri., Oct. 30, 2015 11:00 a.m.
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Location: CK 185
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**Speaker:**Samir RaouafiIdentical pseudospectra**Title:****Abstract:**The theory of pseudospectra is a new tool for studying matrices and linear operators. The traditional tool is the spectrum. It reveals information on the behavior of normal matrices or operators. However, it is less informative as the matrix or the operator is non-normal. Pseudospectra have nevertheless proved to be a powerful tool to study them. In this third lecture, we will proof the Kreiss Matrix Theorem for analytic functions on the unit disc. We will discuss also the behavior of a matrix when we assume an exact knowledge of the resolvent norm.