Mathematical Colloquium
ODELJENJE ZA MATEMATIKU
MATEMATIČKOG INSTITUTA SANU
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Predavanja možete pratiti i online putem MITEAM stranice Odeljenja za matematiku:
https://miteam.mi.sanu.ac.rs/asset/WbsehnSL4ZeTPJo6r
PROGRAM ZA JUL 2025.
Petak, 11.07.2025. u 14:15, Kneza Mihaila 36, sala 301f i
Online
Justin Moore, Cornell University
TODORČEVIĆ'S ULTRAFILTER 𝒰(T)
Over two decades ago, Todorčević defined a uniform filter on ω
1 for each coherent Aronszajn tree
T. He has shown that, in the presence of the Proper Forcing Axiom, this filter 𝒰(
T) is an ultrafilter. Moreover, he showed that under these assumptions, the isomorphism type of this ultrafilter does not depend on the Aronszajn tree and that it's projection to ω is a Ramsey ultrafilter. We extend this analysis by showing that under these assumptions, 𝒰(
T) is on one hand minimal in the Rudin-Keisler order with respect to be uniform and on the other hand, maximal with respect to Tukey's order on directed sets. This is joint work with Tom Benhamou and Luke Serafin.
Zajednicki sastanak sa Seminarom za logiku.
Odeljenje za matematiku je opsti matematicki seminar namenjen sirokoj publici.
Predavanja su prilagodjena matematicarima i onima koji zele da to postanu.
Zoran Petrić, Odeljenje za matematiku Matematickog instituta SANU
