Events for 05/06/2016 from all calendars
Student Working Seminar in Groups and Dynamics
Time: 1:00PM - 2:00PM
Location: BLOC 628
Speaker: Alan Czuroń, IMPAN
Title: Coarse embeddings into uniformly convex Banach spaces
Seminar on Banach and Metric Space Geometry
Time: 3:00PM - 4:00PM
Location: BLOC 220
Speaker: Pavlos Motakis, Texas A&M University
Title: Spreading models and spreading sequences in Banach spaces
Abstract: The notion of a spreading model plays a central role in the linear theory of Banach spaces and it concerns the asymptotic behavior of linear combinations of sequences in such spaces. It has been used in a variety of ways, e.g. to study the behavior of finite block sequences of Schauder bases and even to study properties of bounded linear operators on certain Banach spaces. A notion that goes hand in hand with spreading models is that of a spreading sequence, i.e. a sequence (xi) with the property that the map xi↦ xki extends to a linear isometry for any subsequence (xki) of (xi). We analyze the norm behavior of such sequences that are conditional and break them up into two basic components that are very well behaved. We apply this analysis to prove results such as the fact that every conditional spreading sequence is admitted as a spreading model of a quasi-reflexive Banach space and the fact that C(ωω) admits all possible spreading models, i.e. both the conditional and the unconditional ones. This lecture is based on joint work with S. A. Argyros and B. Sari