added talks and video links

Author: root

_posts/2022-03-25-independent-families-spectra-and-indestructibility.html

@@ -20,7 +20,7 @@
 In this talk, we will consider some recent advances in the area and
 point out to remaining open questions. 
 </p>
-<p><strong><a href=''>Video</a></strong></p>
+<p><strong><a href='https://www.youtube.com/watch?v=yM2L1tXC7SI'>Video</a></strong></p>
 "
 excerpt_separator: <!--more-->
 talk: yes

_posts/2022-04-01-independent-families-spectra-and-indestructibility-part-ii.html

@@ -20,7 +20,7 @@
 In this talk, we will consider some recent advances in the area and
 point out to remaining open questions. 
 </p>
-<p><strong><a href=''>Video</a></strong></p>
+<p><strong><a href='https://www.youtube.com/watch?v=2CxMEPDbqg8'>Video</a></strong></p>
 "
 excerpt_separator: <!--more-->
 talk: yes

_posts/2022-04-19-absolute-undefinability-in-arithmetic.html

@@ -12,7 +12,7 @@
 abstract: "
 <p>I will survey some well-known and some more recent undefinability results about models of Peano Arithmetic. I want to contrast first-order undefinability in the standard model with a much stronger notion of undefinability which is suitable for resplendent models, and use the results to motivate some more general questions about the nature of undefinability.
 </p>
-<p><strong><a href=''>Video</a></strong></p>
+<p><strong><a href='https://www.youtube.com/watch?v=y6s8fDYnV6A'>Video</a></strong></p>
  ​"
 excerpt_separator: <!--more-->
 talk: yes

_posts/2022-04-22-do-these-ultrafilters-exist-i-preservation-by-forcing.html

@@ -0,0 +1,34 @@
+---
+layout: talk
+title: Set Theory Seminar
+talk_title: Do these ultrafilters exist, I: preservation by forcing
+categories: set-theory-seminar
+date: 2022-04-22
+semester: spring-2020
+speaker_first: Andreas
+speaker_last: Blass
+speaker_website: 
+affiliation: University of Michigan
+abstract: "
+<p>
+This is the first of two talks devoted to two properties of
+ultrafilters (non-principal, on omega) for which the question 'Do such
+ultrafilters exist?' is open. In this talk, I'll discuss the property
+of being preserved by some forcing that adds new reals. Some forcings
+destroy all ultrafilters, and some (in fact many) ultrafilters are
+destroyed whenever new reals are added, but it is consistent with ZFC
+that some ultrafilters are preserved when some kinds of reals are
+added. I plan to prove some of these things and describe the rest.
+I'll also describe a combinatorial characterization, due to Arnie
+Miller, of preservable ultrafilters.
+</p>
+<p><strong><a href=''>Video</a></strong></p>
+"
+excerpt_separator: <!--more-->
+talk: yes
+note: "<strong>12:15pm</strong> NY time<br>
+<font color='red' size='3'><strong>Virtual</strong> </font>(email <a href='mailto:vgitman@nylogic.org'>Victoria Gitman</a> for meeting id)<br>
+<strong>GC Room 6496</strong>
+
+ "
+---

_posts/2022-04-22-set-theory-tba.html

@@ -0,0 +1,34 @@
+---
+layout: talk
+title: Set Theory Seminar
+talk_title: Do these ultrafilters exist, II: not Tukey top
+categories: set-theory-seminar
+date: 2022-04-29
+semester: spring-2020
+speaker_first: Andreas
+speaker_last: Blass
+speaker_website: 
+affiliation: University of Michigan
+abstract: "
+<p>This is the second of two talks devoted to two properties of
+ultrafilters (non-principal, on omega) for which the question 'Do such
+ultrafilters exist?' is open. In this talk, I'll discuss the property
+of not being at the top of the Tukey ordering (of ultrafilters on
+omega). I'll start with the definition of the Tukey ordering, and I'll
+give an example of an ultrafilter that is 'Tukey top'. It's consistent
+with ZFC that some ultrafilters are not Tukey top. The examples and
+the combinatorial characterizations involved here are remarkably
+similar but not identical to examples and the characterization from
+the previous talk. That observation suggests some conjectures, one of
+which I'll disprove if there's enough time.
+</p>
+<p><strong><a href=''>Video</a></strong></p>
+"
+excerpt_separator: <!--more-->
+talk: yes
+note: "<strong>12:15pm</strong> NY time<br>
+<font color='red' size='3'><strong>Virtual</strong> </font>(email <a href='mailto:vgitman@nylogic.org'>Victoria Gitman</a> for meeting id)<br>
+<strong>GC Room 6496</strong>
+
+ "
+---