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Tuesday, 3 March 2026 - 10:00 to 11:30 <br />
Place: IM, konÃrna
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Speaker: Henrik Wirzenius, Institute of Mathematics, Czech Academy of Sciences<br />
Title: Compactness of compositions of strictly singular operators on direct sums of Baernstein and Schreier spaces
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Abstract <br />
<p>The Banach algebra A is called n-nilpotent if the product of n number of elements in A is zero. If A is n-nilpotent but not (n-1)-nilpotent, then n is the index of nilpotency of A.</p><p><br></p><p>In this talk, I will describe joint work with Niels Laustsen (Lancaster) on the index of nilpotency of the quotient algebra S(X)/K(X), where S(X) and K(X) denote the closed operator ideals of strictly singular operators and compact operators on a given Banach space X, respectively. We determine this index for Banach spaces which are defined using Schreier subsets of the natural numbers, namely finite direct sums of p-convexified Schreier spaces and Baernstein spaces.</p>
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For more information see the seminar web page at <br />
https://www.math.cas.cz/index.php/events/seminar/6
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Set Theory and Analysis mailing list <br />
settfa@math.cas.cz <br />
https://list.math.cas.cz/listinfo/settfa@math.cas.cz
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