Online Activities 27 April – 3 May 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 28

Münster Set Theory Seminar
Time: Tuesday, April 28, 4:15pm CEST
Speaker: Matteo Viale, University of Torino
Title: Tameness for set theory
Abstract: We show that (assuming large cardinals) set theory is a tractable (and we dare to say tame) first order theory when formalized in a first order signature with natural predicate symbols for the basic definable concepts of second and third order arithmetic, and appealing to the model-theoretic notions of model completeness and model companionship.
Specifically we develop a general framework linking generic absoluteness results to model companionship and show that (with the required care in details) a Pi_2-property formalized in an appropriate language for second or third order number theory is forcible from some T extending ZFC + large cardinals if and only if it is consistent with the universal fragment of T if and only if it is realized in the model companion of T.
Part (but not all) of our results are conditional to the proof of Schindler and Asperò that Woodin’s axiom (*) can be forced by a stationary set preserving forcing.

Cornell Logic Seminar
Time: Tuesday, April 28, 2:55pm New York time (20:55pm CEST)
Speaker: Anton Bernsteyn, Carnegie Mellon University
Title: Descriptive combinatorics and distributed algorithms
Abstract: Descriptive combinatorics is the study of combinatorial problems (such as graph coloring) under additional topological or measure-theoretic regularity restrictions. It turns out that there is a close relationship between descriptive combinatorics and distributed computing, i.e., the area of computer science concerned with problems that can be solved efficiently by a decentralized network of processors. In this talk I will outline this relationship and present a number of applications.

April 29

Paris-Lyon Séminaire de Logique
Time:
Wednesday, April 29, 16:00-17:15 CEST
Speaker: Christian Rosendal – University of Illinois at Chicago
Title: Continuity of universally measurable homomorphisms
Abstract: We show that a universally measurable homomorphism between Polish groups is automatically continuous. Using our general analysis of continuity of group homomorphisms, this result is used to calibrate the strength of the existence of a discontinuous homomorphism between Polish groups. In particular, it is shown that, modulo ZF+DC, the existence of a discontinuous homomorphism between Polish groups implies that the Hamming graph on {0, 1}N has finite chromatic number. This solves a classical problem originating in JPR Christensen’s work on Haar null sets.
Information: Join via the link on the seminar webpage 10 minutes before the talk.

April 30

Kurt Gödel Research Center Seminar (organised by Ben Miller)
Time:
Thursday, April 23, 16:00 CEST
Speaker: Sandra Müller, KGRC
Title: How to obtain lower bounds in set theory
Abstract: Computing the large cardinal strength of a given statement is one of the key research directions in set theory. Fruitful tools to tackle such questions are given by inner model theory. The study of inner models was initiated by Gödel’s analysis of the constructible universe LL. Later, it was extended to canonical inner models with large cardinals, e.g. measurable cardinals, strong cardinals or Woodin cardinals, which were introduced by Jensen, Mitchell, Steel, and others.
We will outline two recent applications where inner model theory is used to obtain lower bounds in large cardinal strength for statements that do not involve inner models. The first result, in part joint with J. Aguilera, is an analysis of the strength of determinacy for certain infinite two player games of fixed countable length, and the second result, joint with Y. Hayut, involves combinatorics of infinite trees and the perfect subtree property for weakly compact cardinals κκ.
Information: Talk via zoom.

May 1

Toronto Set Theory Seminar
Time: Friday, May 1, 1:30-3:00pm EDT (19:30-21:00 CEST)
Speaker: Paul Szeptycki
Title: Strong convergence properties and an example from a square-sequence
Abstract: We present an example of a space constructed from square(kappa), answering some questions of Arhangel’skii. Coauthors Bill Chen and Cesar Corral-Rojas.
Information: The talk will take place via zoom: https://yorku.zoom.us/j/925557716.

CUNY Set Theory Seminar
Time: Friday, May 1, 2pm New York time (8pm CEST)
Speaker: Joan Bagaria, Universitat de Barcelona
Title: From Strong to Woodin cardinals: A level-by-level analysis of the Weak Vopenka Principle
Abstract: In May 2019 Trevor Wilson proved that the Weak Vopenka Principle (WVP), which asserts that the opposite of the category of Ordinals cannot be fully embedded into the category of Graphs, is equivalent to the class of ordinals being Woodin. In particular this implies that WVP is not equivalent to Vopenka’s Principle, thus solving an important long-standing open question in category theory. I will report on a joint ensuing work with Trevor Wilson in which we analyse the strength of WVP for definable classes of full subcategories of Graphs, obtaining exact level-by-level characterisations in terms of a natural hierarchy of strong cardinals.
Information: The seminar will take place virtually. Please email Victoria Gitman (vgitman@nylogic.org) for the meeting id.

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 $V_\lambda$.

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.

Boise Extravaganza in Set Theory 2020

Announcement We are pleased to announce that the 2020 Boise Extravaganza in Set Theory (BEST) conference will take place in Ashland, Oregon, on the campus of Southern Oregon University, June 17–18, 2020.
https://www.boisestate.edu/math/best/
BEST is an international conference featuring talks on a broad range of recent advances in research in set theory, logic, and related fields. Researchers from all areas of set theory and logic are welcome. BEST particularly aims to support the careers of young researchers. The conference is organized by the Set Theory and Logic group at Boise State University and is structured as a symposium of the annual meeting of the AAAS, Pacific Division.
Contact best@boisestate.edu or scoskey@boisestate.edu
Organizers Liljana Babinkostova (Boise State University), John Clemens (Boise State University), Samuel Coskey (Boise State University), Marion Scheepers (Boise State University) Scientific support Natasha Dobrinen (University of Denver)
Plenary speakers* David Fernández-Bretón (Universidad Nacional Autónoma de México)* Victoria Gitman (CUNY Graduate Center)* Jun Le Goh (University of Wisconsin)* Lynne Yengulalp (University of Dayton and Wake Forest University)* Joseph Zielinski
Travel grants availableBEST travel grants, supported by the NSF, are an excellent opportunity for student and postdocs to attend and speak at BEST. (If you are in another category and could use funding, contact us as well.) Please share this opportunity with students, postdocs, and colleagues close to you. We strongly encourage members of groups underrepresented in mathematics to apply. Application instructions are located on the conference website.

11th Scandinavian Logic Symposium

* * * Call for papers

SLSS 2020: Eleventh Scandinavian Logic Symposium
University of Bergen, Norway, June 26-28, 2020

Conference website: https://scandinavianlogic2020.w.uib.no/

* * *

The eleventh Scandinavian Logic Symposium (SLSS 2020) will be held at
the University of Bergen, Norway, during 26-28 June, 2020, under the
auspices of the Scandinavian Logic Society. The previous three meetings
of the SLS were held in Gothenburg, Sweden (2018), Tampere, Finland
(2014) and Roskilde, Denmark (2012).

The primary aim of the Symposium is to promote research in the field of
logic (broadly conceived) carried out in research communities in
Scandinavia. Moreover, it warmly invites participation of logicians from
all over the world. The meeting will include invited lectures and a
forum for participants to present contributed talks.

* * * Suggested topics

The scope of SLSS is broad, ranging over the whole areas of Mathematical
and Philosophical Logic, as well as Logical Methods in Computer Science,
Artificial Intelligence, Linguistics, etc. Major topics include (but are
not limited to)
Proof Theory
Constructivism
Model Theory
Set Theory
Computability Theory
Algebra and Logic
Categorical Logic
Modal and Temporal Logics
Dynamic Logics Logic and Computer Science
Logic in AI and Multi-Agent Systems
Logic and Linguistics
Philosophical Logic
Philosophy of Logic, Mathematics and Computation

* * * Submissions

Abstracts of contributed talks, in PDF format, not exceeding two A4
(11pt) pages, should be submitted by April 3, 2020, through EasyChair:
https://easychair.org/conferences/?conf=slss2020
Abstracts should be typeset following the format of a LaTeX style file
posted on the conference website, or in a similar format if you prefer
to not use LaTeX.

* * * Important dates

Final programme: May 29, 2020
Conference: June 26-28, 2020

* * * Invited speakers

To be announced

* * * Programme committee

Co-chairs: Åsa Hirvonen (Helsinki) and Thomas Ågotnes (Bergen)

Members:
Thierry Coquand (Gothenburg)
Nina Gierasimczuk (DTU)
Lauri Hella (Tampere)
Lars Kristiansen (Oslo)
Antje Rumberg (Stockholm)
Asger Törnquist (Copenhagen)
Michal Walicki (Bergen)
Fan Yang (Helsinki)

* * * Organising committee

Shuliang Dong
Truls Pedersen
Marija Slavkovik
Mina Young Pedersen
Thomas Ågotnes

* * * Location

SLSS 2020 will take place at the University of Bergen, located in the
center of Bergen in Norway.

SLSS 2020 is collocated with the Nordic Logic School, 22-26 June, 2020.

* * * Registration

Details concerning registration will be announced during the spring 2020.

* * * Contact

All questions regarding the symposium should be emailed to slss@uib.no.

Logic Colloquium 2020, Poznan

Poznan, Poland, 13-18.07.20120

https://lc2020.pl/

The Logic Colloquium is the European Summer Meeting of the Association for
Symbolic Logic, that in 2020 will be held from 13th to 18th of July at the
Adam Mickiewicz University, Poznan, Poland. It is organized jointly by the
AMU Faculties: of Psychology and Cognitive Science and of Mathematics and
Computer Science.

The latest meetings took place in Helsinki (2015), Leeds (2016), Stockholm
(2017), Udine (2018) and Prague (2019).

The Association for Symbolic Logic is an international organization
supporting research and critical studies in logic. Its primary function is
to provide an effective forum for the presentation, publication, and
critical discussion of scholarly work in this area of inquiry.

IMPORTANT DATES
January 31st, 2020 registration opens
March 31st, 2020 deadline for abstract submission
April 13th, 2020 deadline for student travel awards applications
May 25th, 2020 camera-ready abstracts due
June 13th, 2020 early payments deadline
July 7th, 2020 late payments deadline

Enquiries should be sent to:
– lc2020@ppnt.poznan.pl concerning travel, registration and other matters outside the scientific program
– szymon.chlebowski@amu.edu.pl concerning abstracts
– andrzej.gajda@amu.edu.pl concerning scientific program
– natalia.zyluk@amu.edu.pl concerning financial support

PROGRAM COMMITTEE
Boris Zilber, University of Oxford – chair
Wojciech Buszkowski, Adam Mickiewicz University in Pozna?
Anuj Dawar, University of Cambridge
Giuseppe Primiero, University of Milan
Henry Towsner, University of Pennsylvania
Matteo Viale, University of Torino

TUTORIAL SPEAKERS
Krzysztof Krupinski, University of Wroc?aw
Andrew Marks, University of California Los Angeles

PLENARY SPEAKERS
Elisabeth Bouscaren, CNRS – Université Paris-Sud (Gödel Lecture)
Linda Westrick, Pennsylvania State University
Benoit Monin, Créteil University
Noam Greenberg, Victoria University of Wellington
Vera Fischer, University of Viena
Luca Motto Ros, University of Turin
Elaine Pimentel, Federal University of Rio Grande do Norte
Frank Pfenning, Carnegie Mellon University
Johan van Benthem, University of Amsterdam
Ryan Williams, Massachusetts Institute of Technology
Artem Chernikov, University of California Los Angeles

SPECIAL SESSIONS
Set Theory
Model Theory
Modal and Epistemic Logic
Proofs and Programs
Computability
Logic and Cognitive Science and Linguistics

SUBMISSIONS
Abstracts of contributed papers must be submitted as pdf files, via EasyChair (go to: https://easychair.org/conferences/?conf=lc2020). Abstract should be prepared according to the ASL instruction using the ASL abstract style (http://aslonline.org/rules-for-abstracts/). The deadline for submissions is March 31st, 2020.

Upon notification of acceptance, authors will be requested to submit the LaTeX source files. Abstracts are published as part of the meeting report in The Bulletin of Symbolic Logic only if at least one author is a member of the ASL at the time the report is sent for publication. Abstracts of contributed papers submitted by ASL members will be published in The Bulletin of Symbolic Logic, provided that they satisfy the Rules for Abstracts.

FEES
– early payments (deadline: June 13th, 2020): 250 EUR (regular), 200 (reduced);
– late payments (deadline: July 7th, 2020): 350 EUR (regular), 300 (reduced).
Reduced fees will be applied to students and PhD students, and participants from countries with developing economies

Student travel awards
The ASL will award modest travel awards to attend LC 2020, for PhD students and recent students (at most 2 years from defence). For details, see: http://aslonline.org/student-travel-awards/. Applications should be sent between January 31st–April 13th, 2020. Application must contain a short description of applicant’s project, their status and the sum requested. It should be followed by a supervisor’s recommendation.

Udine Workshop on Singular Cardinals

We are happy to announce the upcoming “Udine Workshop on Singular Cardinals”, that will be held in Udine (Italy) on 6-7 July 2020. It will be held at Palazzo di Toppo Wassermann, a prestigious 18th-century palace. Singular cardinals are transversal to set theory and beyond, and this will be an occasion to bring together researchers working on singular cardinals and share the latest developments on this topic.

Organizers:Vincenzo Dimonte (University of Udine)
Mirna Dzamonja (The University of East Anglia)
Luca Motto Ros (University of Torino)

Talks:James Cummings (Carnegie Mellon University)
Péter Komjáth (Eötvös Loránd University)
Menachem Magidor (The Hebrew University of Jerusalem) *
Itay Neeman (UCLA) *
Assaf Rinot (Bar-Ilan University)
Jouko Väänänen (University of Helsinki)
* To confirm

Website: https://users.dimi.uniud.it/~vincenzo.dimonte/WSC2020.html

There will be some slots open for contributed talks, and all the interested researchers and students are encouraged to apply. To propose a contributed talk, please write to vincenzo.dimonte@uniud.it by May the 31st.

For further information, contact vincenzo.dimonte@uniud.it

Young Set Theory Workshop + SETTOP 2020

YSTW 2020 “Young Set Theory Workshop”
SETTOP 2020 “Novi Sad Conference in Set Theory and General Topology”

We are doubly pleased to announce two conferences that will take place in Novi Sad in August:
Young Set Theory Workshop 2020, from August 19th to August 22nd
Novi Sad Conference in Set Theory and General Topology 2020, from August 24th to August 27th.

Tutorial speakers for YSTW 2020:
Martin Goldstern (Vienna)
Michael Hrušák (Morelia)
John Krueger (Denton, TX)
Paul Larson (Oxford, OH)

Postdoctoral speakers for YSTW 2020:
Jeffrey Bergfalk (Morelia)
Gabriel Goldberg (Berkeley, CA)
Asaf Karagila (Norwich)
Miguel Moreno (Vienna)
Šárka Stejskalová (Prague)

Invited speakers for SetTop 2020:
Mirna Džamonja (Norwich, Paris)
Istvan Juhász (Budapest)
Piotr Koszmider (Warsaw)
Ashutosh Kumar (Singapore)
Philipp Lücke (Bonn)
Yinhe Peng (Beijing)
David Schrittesser (Vienna)
Stevo Todorčević (Toronto, Paris)
Anush Tserunyan (Montreal)

Program Committee:
Vera Fischer (Vienna)
Justin Moore (Ithaca, NY)
Dilip Raghavan (Singapore)
Assaf Rinot (Ramat Gan)

A poster session will be organized during the course of YSTW. Participants of SetTop are welcome to present short talks.

Important dates:
Early bird registration: until March 15th
Registration: until June 15th
Abstract submission and online fee payment: until July 15th

Fees
YSTW Conference Fee: 150 euros; Early bird payment: 130 euros; Payment on spot: 170 euros
SetTop Conference Fee: 150 euros; Early bird payment: 130 euros; Payment on spot: 170 euros
Fee for both conferences: 270 euros; Early bird payment: 230 euros; Payment on spot: 300 euros
Fee for an accompanying person: 70 euros; Payment on spot: 80 euros

Contact e-mail: settop@dmi.uns.ac.rs
For information about the four previous installments of SetTop please visit the web site www.dmi.uns.ac.rs/settop.
Please feel free to forward this message to anyone who might be interested.
For more details follow instructions on our web page www.dmi.uns.ac.rs/settop/2020

Hoping to see you in Novi Sad,

on behalf of the Organizing Committee,
Aleksandar Pavlović and Boris Šobot

Colloquium Logicum 2020 Konstanz

—————————————-
COLLOQUIUM LOGICUM 2020
https://colloquiumlogicum2020.com/

23-26 September 2020, Konstanz, Germany
—————————————-

The Colloquium Logicum is organized every two years by the “Deutsche
Vereinigung fuer Mathematische Logik und fuer Grundlagenforschung der Exakten
Wissenschaften” (DVMLG). In 2020, it will be hosted at the University of
Konstanz. The conference will cover the whole range of mathematical logic and
the foundations of the exact sciences. In addition to all fields of
mathematical logic, this includes the philosophy of the exact sciences, logic
in philosophy, and logic in computer science and artificial intelligence.

Keynote Speakers.

Laurent Bienvenu (Bordeaux)
Catrin Campbell-Moore (Bristol)
Wesley Holliday (Berkeley)
Christian Ikenmeyer (Liverpool)
Angeliki Koutsoukou-Argyraki (Cambridge)
Alison Pease (Dundee)
Margaret Thomas (West Lafayette)

In addition to the keynote talks, there will be a “PhD Colloquium” with invited
presentations of excellent recent PhD graduates.

Programme Committee: C. Antos, M. Carl, D. Cenzer, E. Fokina, I. Halupczok, D.
Klein, S. Kuhlmann (chair), O. Linnebo, B. Loewe, M. Ziegler.

An invitation for submission of abstracts for presentations will be issued
soon.

Colloquium Logicum 2020 is generously funded by the Deutsche
Forschungsgemeinschaft (DFG-grant LO 834/18-1).