# Seminar at SMU Delhi

September 28, 2011 (Wednesday) , 3:30 PM at Webinar
Speaker: Bipul Saurabh, Indian Statistical Institute, Delhi
Title: Extensions of $C^*$-algebra by compact operators.
Abstract of Talk
We will show that the set of extensions of a unital, separable, nuclear $C^*$ algebra by compact operators modulo unitary equivalence forms an abelian group. As a consequence, we give a complete classification of essentially normal operators having same essential spectrum modulo an appropriate equivalence relation. These results are part of the celebrated Brown-Douglas-Fillmore theory.