### Talks during the spring term 2013

Wed 16.1.2013 12-14, C124

Miika Hannulan and Juha Kontinen: Remarks on natural deduction in dependence logic

Wed 23.1.2013 12-14, C124

Camilo Argoty (Bogota): Elementary Classes and Metric Abstract Elementary Classes asociated to Hilbert spaces operator algebras acting over them.

Abstract: We study different formalisims for Hilbert spaces and operator algebras acting over them, including continuous first order and metric abstract elementary class. We present different examples and show where each one of these is more suitable.

Slides of talk.

Wed 30.1.2013 12-14, C124

Daisuke Ikegami: Stationary Tower Forcing (first part of tutorial)

Wed 6.2.2013 12-14, C124

John Baldwin: Constructing Atomic Models in the Continuum (first part of tutorial lecture 1 lecture 2 lecture 3)

Wed 13.2.2013 13.00-14, C124

Kaisa Kangas: On a cover of the multiplicative group of complex numbers

Wed 20.2.2013 12-14, C124

No seminar.

Wed 27.2.2013 12-14, C124

No seminar

Wed 6.3.2013 12-14, C124, rescheduled to Fri 8.3. 13-15

Fredrik Engström: Models of arithmetic, standardness and expansions

Abstract: A structure is resplendent if every existential second-order sentence consistent with the theory of the structure holds in the structure. Similar notions have been investigated in the contexts of models of Peano Arithmetic and been shown to be equivalent. We introduce a notion, transplendency, which is strictly stronger than resplendency and in some sense the equivalent of resplendency on models of PA with a standardness predicate. Several connections with systems of second-order arithmetic and PA with a standardness predicate will be stated. We will also present some problems that remain to be solved. This is joint work with Richard W. Kaye.

Wed 13.3.2013 12-14, C124

Ove Ahlman and Vera Koponen (Uppsala): Automorphism groups and limit laws of random nonrigid structures

Abstract: Let V be a finite relational vocabulary with at least one relation symbol with arity greater than one. Let S_n be the set of V-structures with universe {1,...,n}. It is well known that the proportion of structures in S_n with trivial automorphism group approaches 1 as n tends to infinity. It is also well known that S_n satisfies a zero-one law; so the same holds for the set of all structures in S_n with trivial automorphism group. But what can be said about structures in S_n with nontrivial automorphism group? Besides an article by P. Cameron from 1980 there seems to be no previous work in this direction. We will present some results about random structures with nontrivial automorphism group, such as limit laws and results about the typical automorphism group. In general one can say that simple symmetries are overwhelmingly more usual than more complicated symmetries.

Wed 20.3.2013 12-14, C124

Iegor Reznikoff (Paris): The Memory Paradox

Wed 27.3.2013 12-14, C124**Cancelled**

Wed 3.4.2013 12-14, C124

Eastern holiday, no seminar

Wed 10.4.2013 12-14, C124

Jouko Väänänen: Second order categoricity without second order definable well-order

Wed 17.4.2013 12-14, C124

Pietro Galliani: Inclusion logic and fixpoints

Wed 24.4.2013 12-14, C124

Jouko Väänänen: Second order categoricity without second order definable well-order (continued)

Wed 1.5.2013 12-14, C124

Vappu, no seminar

Wed 8.5.2013 12-14, C124

Mikko Männikkö: Non-Fregean approach to independence friendly logic

Wed 15.5.2013 12-14, C123 - note: different room

Juliet Floyd (Boston university): Universalism (second part of tutorial, the first being on Tuesday 14.5. at 12-14 in B120)