## Past Seminars- Logic Set Theory

• Kameran Kolahi
Mon Jun 5, 2017
4:00 pm
We explore the applications of the pcf theory to cardinal estimates.
• Kameran Kolahi
Mon May 22, 2017
4:00 pm
We present a proof of a theorem of Shelah that if a is a progressive interval of regular cardinals then then |pcf(a)| < |a|^{+4}.
• Omer Ben Neria
Mon May 1, 2017
4:00 pm
Mutual stationarity is a notion of infinite products of stationary sets introduced by Foreman and Magidor. The assertion that an infinite sequence of stationary sets is mutually stationary has a natural model theoretic interpretation and can be viewed as a strengthening of the Loewenheim-Skolem property.
• Kameran Kolahi
Mon Apr 24, 2017
4:00 pm
We develop basic properties of generators of J_{\lambda^+}(a). Then we present the theorem of Shelah that under certain circumstances, max(pcf(a)) has the largest possible cardinality.
• Kameran Kolahi
Mon Apr 17, 2017
4:00 pm
For appropriate sets of regular cardinals $a$, we show that for every cardinal $\lambda$ there is a subset $c$ of $a$ that generates $J_{< \lambda^+}(a)$ over $J_{< \lambda}(a)$.
• Nam Trang
Mon Apr 3, 2017
4:00 pm
We investigate various aspects of compactness of \omega_1 under ZF+ DC (the Axiom of Dependent Choice). We say that \omega_1 is X-supercompact if there is a normal, fine, countably complete nonprincipal measure on \powerset_{\omega_1}(X) (in the sense of Solovay). We say \omega_1 is X-strongly compact if there is a fine, countably complete...
• Gabriel Conant
Mon Mar 13, 2017
4:00 pm
The additive group of integers is a well-studied example of a stable group, whose definable sets can be easily and explicitly described. However, until recently, very little has been known about stable expansions of this group. In this talk, we examine the relationship between model-theoretic stability of expansions of the form (Z,+,0,A), where A...