Michael Hartz (St. Louis): Interpolating sequences and Kadison-Singer. Oberseminar C*-Algebren
am Dienstag, 19.12.2017 15:15 im Raum N2
A sequence $(z_n)$ in the unit disc is called an interpolating sequence for $H^\infty$ if for every bounded sequence of values $(w_n)$, there exists a bounded analytic function $f$ in the disc such that $f(z_n) = w_n$ for all $n$. Such sequences were characterized by Lennart Carleson.
I will talk about a generalization of Carleson's theorem to other classes of functions. The proof of this result uses the solution of the Kadison-Singer problem due to Marcus, Spielman and Srivastava. This is joint work with Alexandru Aleman, John McCarthy and Stefan Richter.
Angelegt am Donnerstag, 12.10.2017 15:03 von elke
Geändert am Montag, 23.10.2017 09:15 von elke
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Olaf Schnürer: Conservative descent for semi-orthogonal decompositions, Oberseminar Algebra und Geometrie
am Mittwoch, 20.12.2017 16:15 im Raum M4
Motivated by the local flavor of several well-known semi-orthogonal decompositions in algebraic geometry, we introduce a technique called conservative descent, which shows that it is enough to establish these decompositions locally. The decompositions we have in mind are those for projectivized vector bundles and blow-ups (due to Orlov) and root stacks (due to Ishii and Ueda). Our technique simplifies the proofs of these decompositions and establishes them in greater generality. If time permits, we may also discuss semi-orthogonal decompositions for Brauer-Severi varieties (due to Bernardara). This is joint work with Daniel Bergh (Copenhagen).