This Week in Logic at CUNY


Models of Peano Arithmetic
Monday, March 19, 2012 7:00 pm Room 4214-03
Professor David Marker (University of Illinois at Chicago)
The Mourgues Rassayre Theorem


Set Theory Seminar
Friday, March 23, 2012 10:00 am GC 6417
Professor Gunter Fuchs (The City University of New York)
Contructing a Souslin almost Kurepa tree

Abstract. In joint work with Joel Hamkins, we investigated various
strengthenings of rigidity of a Souslin tree. Many of these notions
come from viewing the Souslin tree T as a notion of forcing. For
example, T is absolutely rigid of T is rigid after forcing with T. A
quite intriguing strong form of rigidity is the unique branch
property, which says that forcing with T adds precisely one branch to
T. In our collaborative work, we were able to establish a complete
diagram of implications and non-implications between these and various
other forms of rigidity. One question that arose was how badly a rigid
Souslin tree can violate the unique branch property. In this talk, I
am going to sketch the construction of a rigid Souslin tree T that is
almost Kurepa, which means that after forcing with T, T becomes a
Kurepa tree – so it violates the unique branch property as badly as

Model Theory Seminar
Friday, March 23, 2012 12:30 pm GC 6417
Professor Jouko Väänänen (University of Helsinki and University of Amsterdam)
On second-order model theory III

Abstract. This mini course will cover the following topics: second
order characterizable structures, Henkin models, Completeness Theorem,
internal categoricity, and existence of second order equivalent
non-isomorphic models.

Logic Workshop
Friday, March 23, 2012 2:00 pm GC 6417
Professor Curtis Franks (Department of Philosophy, University of Notre Dame)
Gödel’s last thought on Gentzen’s consistency proof

Abstract. A transcript of a series of conversations between Kurt Gödel
and Sue Toledo from the years 1972 to 1975 was recently made available
and published in Kennedy and Kossak 2011. Among the most striking
remarks recorded in these notes is Gödel’s claim that Hilbert’s
program “was completely refuted,” though by Gerhard Gentzen’s work
and not by Gödel’s own results. This is exactly opposite the customary
appraisal of these matters. Drawing from the details of Gödel’s late
thought and some basic technical observations, we can understand how
Gödel could make such a claim and begin to appreciate an attitude
towards foundations that differs greatly from familiar ideas.

Next Week in Logic at CUNY:

– – – – Monday, Mar 26, 2012 – – – –

Models of Peano Arithmetic
Monday, March 26, 2012 7:00 pm Room 4214-03
Professor Alfred Dolich (Kingsborough Community College)
Omega-1 like models of Presburger arithmetic

– – – – Tuesday, Mar 27, 2012 – – – –

– – – – Wednesday, Mar 28, 2012 – – – –

– – – – Thursday, Mar 29, 2012 – – – –

– – – – Friday, Mar 30, 2012 – – – –

Model Theory Seminar
Friday, March 30, 2012 12:30 pm GC 6417
Mr. Manuel Alves (Ph.D. Program in Mathematics, Graduate Center of CUNY)
Introduction to elementary duality for modules

– – – – Other Logic News – – – –

– – – – Web Site – – – –

The majority of this information, including an interactive calendar of
future events, can be found at our website:


Leave a Reply

Your email address will not be published. Required fields are marked *

Time limit is exhausted. Please reload CAPTCHA.