Online Activities 20-26 April 2020

This is a list of online talks in set theory next week.

For a complete list see online activities. In case we missed an upcoming talk, please email matteo.viale@unito.it, boban.velickovic@math.univ-paris-diderot.fr or philipp.schlicht@bristol.ac.uk.

April 21

Münster Set Theory Seminar
Time: Tuesday, April 21, 4:15pm CEST
Speaker: Farmer Schlutzenberg, University of Münster
Title: Non-definability of embeddings $j:V_\lambda\to V_\lambda$
Abstract: Assume $\ZF$. We show that there is no limit ordinal $\lambda$ and $\Sigma_1$-elementary $j:V_\lambda\to V_\lambda$ which is definable from parameters over $V_\lambda$.
Information: The seminar will be held remotely via zoom. Please contact rds@wwu.de ahead of time in order to participate.

April 22

New York Logic Seminar (MOPA)
Time: Wednesday, April 22, 7pm New York time (Thursday, April 23, 1am CEST)
Speaker: Corey Switzer, CUNY
Title: Hanf Numbers of Arithmetics
Abstract: Recall that given a complete theory T and a type p(x) the Hanf number for p(x) is the least cardinal κ so that any model of T of size κ realizes p(x) (if such a κ exists and ∞ otherwise). The Hanf number for T, denoted H(T), is the supremum of the successors of the Hanf numbers for all possible types p(x) whose Hanf numbers are <∞. We have seen so far in the seminar that for any complete, consistent T in a countable language H(T)≤ℶω1 (a result due to Morley). In this talk I will present the following theorems: (1) The Hanf number for true arithmetic is ℶω (Abrahamson-Harrington-Knight) but (2) the Hanf number for False Arithmetic is ℶω1 (Abrahamson-Harrington)
Information: The seminar will take place virtually. Please email Victoria Gitman for the meeting id.

Bar-Ilan University and Hebrew University Set Theory Seminar
Time: Wednesday, April 22, 11am IST (10am CEST)
Speaker: Jing Zhang
Title: Transformations of the transfinite plane
Abstract: We discuss the existence of certain transformation functions turning pairs of ordinals into triples (or pairs) of ordinals, that allows reductions of complicated Ramsey theoretic problems into simpler ones. We will focus on the existence of various kinds of strong colorings. The basic technique is Todorcevic’s walks on ordinals. Joint work with Assaf Rinot.
Information: The zoom meeting ID is 243-676-331 and no password.

April 23

Kurt Gödel Research Center Seminar (organised by Ben Miller)
Time:
Thursday, April 23, 16:00 CEST
Speaker: Noé de Rancourt, KGRC
Title: Weakly Ramsey ultrafilters
Abstract: Weakly Ramsey ultrafilters are ultrafilters on ωω satisfying a weak local version of Ramsey’s theorem; they naturally generalize Ramsey ultrafilters. It is well known that an ultrafilter on ωω is Ramsey if and only if it is minimal in the Rudin-Keisler ordering; in joint work with Jonathan Verner, we proved that similarly, weakly Ramsey ultrafilters are low in this ordering: there are no infinite chains below them. This generalizes a result of Laflamme’s. In this talk, I will outline a proof of this result, and the construction of a counterexample to the converse of this fact, namely a non-weakly Ramsey ultrafilter having exactly one Rudin-Keisler predecessor. This construction is partly based on finite combinatorics.
Information: Talk via zoom.

April 24

CUNY Set Theory Seminar
Time: Friday, April 24, 2pm New York time (8pm CEST)
Speaker: Arthur Apter, CUNY
Title: Indestructibility and the First Two Strongly Compact Cardinals
Abstract: Starting from a model of ZFC with two supercompact cardinals, I will discuss how to force and construct a model in which the first two strongly compact cardinals κ1 and κ2 are also the first two measurable cardinals. In this model, κ1’s strong compactness is indestructible under arbitrary κ1-directed closed forcing, and κ2’s strong compactness is indestructible under Add(κ2,λ) for any ordinal λ. This answers a generalized version of a question of Sargsyan.
Information: The seminar will take place virtually. Please email Victoria Gitman (vgitman@nylogic.org) for the meeting id.

2020 Logic Colloquium postponed to 2021

Due to public health concerns regarding COVID-19, the ASL Executive
Committee, in consultation with the local organizers and the ASL European
Committee, has made the decision to postpone the 2020 Logic Colloquium.

It will take place on July 19-24, 2021, approximately a year later than
originally scheduled, in the same location:  Poznan, Poland.

The Executive Committee very much regrets having had to make this decision,
but considers it the only responsible course of action.  Please see the LC 2020 website for further details.

Any questions may be addressed to the ASL Secretary-Treasurers Russell
Miller and Reed Solomon, and/or the the ASL office, at asl@uconn.edu.

We hope to see you in Poznan in 2021!

Best, Shannon Miller

Association for Symbolic Logic
University of Connecticut
Phone: (860) 486-3989

Position as Maitre de conférence in mathematical logic, University of Paris (France), Deadline: 26 March 2020

There is currently an opening for a Maitre de Conférence position (Assistant Professor) in Mathematical Logic at the University of Paris in 2020. Set Theory is one of the priority areas for this position. The code of the position is 1192.

In order to apply candidates should already have a qualification that was done of the site Galaxie. More information on the position can be found here. Applications are also done through Galaxie.. Letters of recommendation should be submitted on the following website of the Institut Mathématiques de Jussieu.

Please note that the deadline is March 26 at 16h Paris time and no applications will be accepted after that date. The first meeting of the hiring committee will be on May 11 and the interviews will be on May 19. The final decision will be made soon afterwards.

XV International Luminy workshop in Set Theory

The 15th International Luminy workshop in set theory took place at the CIRM, Luminy near Marseille September 23-27 2019. The program and slides of some of the talks can be seen here:

https://conferences.cirm-math.fr/2052.html

Videos of some of the lectures can be seen here.

The conference photo is below.

Postdoctoral program: Fondation Sciences Mathématiques de Paris – deadline December 2 2019

The Fondation Sciences Mathématiques de Paris provides funding for 20 years of post-doctoral fellowships in mathematics and in computer science for the 2020-2021 academic year. Appointed fellows will hold one or two-year positions in affiliated research laboratories, starting in October 2020.

The deadline for applications is December 2 2019.

If you are interested in applying in logic and set theory, please contact: Boban Velickovic

Position as Maitre de conférence in mathematical logic, Paris (France), Deadline: 24 Oct 2019

There will be an opening for a Maitre de Conférence position (Assistant Professor) in Mathematical Logic at the University of Paris Diderot in 2020. Set Theory will be one of the priority areas. The hiring procedure in France requires candidates to go through a qualification procedure. This procedure is done by the CNU (ministry committee). More information can be found on the following website:

https://www.galaxie.enseignementsup-recherche.gouv.fr/ensup/cand_qualification_droit_commun.htm

In order to initiate the procedure the candidates should create an account on the website

https://galaxie.enseignementsup-recherche.gouv.fr/antares/can/index.jsp

The deadline for doing this is October 24 2019. The candidates then have till December 17 to upload their file (cv, publications, etc) . The committee then examines the files and the results are announced in February 2020. The actual positions will be announced in March 2020, but in order to apply the candidates already need to have the qualification.

Patrick Dehornoy (1952-2019)

https://smf.emath.fr/actualites-smf/deces-de-patrick-dehornoy

Le Laboratoire de Mathematique Nicolas Oresme ainsi que tout le personnel
de l’universite qu’il a cotoye ont l’immense tristesse de vous faire part
du deces, mercredi 4 septembre, de leur collegue

Patrick DEHORNOY
Professeur emerite

Il est difficile de trouver les mots pour rappeler son engagement dans la
Recherche, sa vision scientifique et le role qu’il a pu jouer, tant au
niveau local que national, dans le developpement des mathematiques et de
leur valorisation.

Ses travaux portent sur la theorie des ensembles et l’algebre. Il est a
l’origine de la fondation du LMNO, et a ete le premier directeur
scientifique de l’INSMI (Institut National des Sciences Mathematiques et
de leurs Interactions).

Les messages sont a adresser au LMNO, lmno.direction@unicaen.fr.

Position as Maitre de conférence in mathematical logic, Paris (France), Deadline: 6 March 2019

There is currently an opening for a Maitre de Conférence position (Assistant Professor) in Mathematical Logic at the University of Paris 7 in 2019. Set Theory is one of the priority areas for this position. The code of the position is 4424.

In order to apply candidates should already have a qualification that was done of the site Galaxie. More information on the position can be found here. Applications are done through the site COMITEC of the Univerity Paris Diderot. You can import your information from Galaxie. Letters of recommendation should be submitted on the following website of the Institut Mathématiques de Jussieu.

Please note that the deadline is March 6 at 16h Paris time and no applications will be accepted after that date. The first meeting of the hiring committee will be on April 15 and the interviews will be on May 15. The final decision will be made soon afterwards.