Skip to content

Events for July 26, 2017 from General and Seminar calendars

Workshop in Analysis and Probability Seminar

Time: 2:00PM - 2:50PM

Location: BLOC 220

Speaker: Cleon Da Silva Barroso, Universidade Federal do Ceará

Title: Existence of shift basic sequences and its implications

Abstract: It is shown that every seminormalized sequence with no weakly convergent subsequences admits a wide-(s) subsequence which is shift equivalent. Also, basic sequences with shiftable properties are studied. They give rise to a generalized form of the Pelczynski's property (u), called property (su). It is shown that every Banach space with a conditional spreading basis has property (su). As a consequence the classical James’ space J2 has property (su), which nicely contrast with the fact that it does not have Pelczynski's property (u).

Workshop in Analysis and Probability Seminar

Time: 3:00PM - 3:50PM

Location: BLOC 220

Speaker: Jesus Suarez, University of Extremadura

Title: Weak Hilbert structures on twisted sums of \ell_2

Abstract: We study when a twisted sum of \ell_2 with itself may be close to be a Weak Hilbert space, namely if it may have the property (H) or to be asymptotically \ell_2 for example. We show that \ell_2 is the only symmetric twisted sum of \ell_2 that may be a Weak Hilbert space. On the other hand, we may prove that there is a nontrivial twisted sum of \ell_2 having the E(n,n,K)-property introduced by Nielsen and Tomczak-Jaegermann. Several open problems will be explained.