# Author: ests

# Third Hausdorff Medal 2017

Ladies and gentlemen, dear friends and colleagues!

It is my honor and pleasure to announce the winner of the third Hausdorff medal of the European Set Theory Society. The Hausdorff medal is awarded biennially (i.e. once every second year) for the most influential work in set theory published in the five years preceding the awarding of the medal. The prize committee, that consists of the members of the Board of Trustees of the Society, decided that the third Hausdorff medal is awarded to Maryanthe Malliaris and Saharon Shelah for their work outlined in the paper:

General topology meets model theory, on p and t. Proc. Natl. Acad. Sci. USA 110 (2013), no. 33, 13300-13305,

and then expounded in the detailed, 60 page long version:

Cofinality spectrum theorems in model theory, set theory, and general topology. J. Amer. Math. Soc. 29 (2016), no. 1, 237-297.

LAUDATION:

Malliaris and Shelah solved two long-standing and fundamental problems:

First, they solved a more than 50 year old set theoretic problem, going back to Rothberger, by showing that the well-known and important cardinal characteristics p and t of the continuum are actually equal.

Secondly, they solved a 40 year old problem in model theory by showing that the maximality in Keislers order is not characterized by the strict order property, but that a weak order property called SOP2 suffices.

Both results follow from a brilliant analysis of definability in ultraproducts of finite linear orders. This analysis is also unique in proving that there are theories more complex than the stable, i.e. minimal theories but less complex than the maximal class in Keisler’s order.

To conclude, this important work of Malliaris and Shelah opens the door for significant and fruitful new interactions between set theory and model theory.

Saharon Shelah, Maryanthe Malliaris, István Juhász, Jouko Väänänen – photo by Joan Bagaria

István Juhász, Saharon Shelah, Maryanthe Malliaris, Jouko Väänänen – photo by Joan Bagaria

# Upcoming set theory meetings

*May 29:* Borel Reducibility of Equivalence Relations, Lausanne

*June 20-25:* Set Theoretic Pluralism – Symposium 2

*June 26-30:* Seventeenth Latin American Symposium on Mathematical Logic, Puebla, Mexico

*June 27-30:* 32nd Summer Conference on Topology and its Applications, Dayton, US

*July 3-7:* 6th European Set Theory Conference, Budapest

*July 10-14:* 10th Young Set Theory Workshop, Edinburgh

*July 10-14:* The 15th Asian Logic Conference, Korea

*July 14-25:* Graduate summer school: Classification problems in ergodic theory, Irvine

*July 31-August 4:* Applications of model theory to operator algebras, Houston

*August 2-4:* A conference on the occasion of Jensen’s 80th birthday, Münster

*August 7-11:* Nordic Logic Summer School 2017, Stockholm

*August 14-18:* Boolean Algebras, Lattices, Universal Algebra, Set Theory, Topology (BLAST), Nashville

*August 14-20:* Logic Colloquium 2017, Stockholm

*August 20-September 1:* Frontiers of Selection Principles, Warsaw

*September 3-9:* Set Theoretic Methods in Topology and Analysis, Bedlewo, Poland

*September 6-8:* Descriptive set theory in Torino

*September 7-12:* Set theoretic & Topological methods in Model Theory, Tezpur, India

*September 10-12:* Homogeneous structures, permutation groups, and connections to set theory, in honour of the 70th birthday of John Truss, Leeds

*September 15-17:* Simon Thomas: the first 60 years, Rutgers

*October 9-13:* The 14th international Luminy workshop on set theory, CIRM, Marseille

*November 6-9:* RIMS set theory meeting, Kyoto

*November 13-17:* Second Pan Pacific International Conference on Topology and its Applications, Busan, South Korea

# European Set Theory Conference – deadline extended

Dear Colleague,

The Early Bird registration deadline to the 6th European Set theory

Conference has been extended to April 30th.

*Homepage of the meeting*:

https://sites.google.com/site/6thestc/home

*Registration*:

At the Registration page

of the above homepage of the meeting.

With best regards,

The Organizers

# Münster Set Theory Conference

A conference on the occasion of Ronald B. Jensen’s 80th birthday will take place from Aug 02–Aug 04, 2017 at the Institut für Mathematische Logik und Grundlagenforschung, WWU Münster.

List of speakers:

Gunter Fuchs (CUNY)

Moti Gitik (Tel Aviv University)

Menachem Magidor (Jerusalem)

Adrian Mathias (Reunion)

Bill Mitchell (U. Florida)

Itay Neeman (UCLA)

Grigor Sargsyan (Rutgers)

John Steel (Berkeley)

W. Hugh Woodin (Harvard)

Martin Zeman (UC Irvine)

Organizers: Menachem Magidor (Jerusalem), Ralf Schindler (Münster), John Steel (Berkeley), W. Hugh Woodin (Harvard)

In order to register for this conference, please send an email to Ralf Schindler at rds@wwu.de. There is no registration fee, but we will ask participants for a small donation in order to cover expenses for coffee and cookies.

We can offer a few grants to doctoral students or post-doctoral researchers who are interested in attending this meeting and who do not have access to funding from a third source. If this applies to you, then please contact Ralf Schindler at rds@wwu.de.

# Extended deadline for the Young Set Theory Workshop 2017

Due to the availability of further places, the deadline for registering to the “New Directions in the higher infinite” (Young Set Theory) workshop has been extended to the 28th of April 2017. You can find the registration link at the following website:

http://icms.org.uk/workshops/higherinfinite

which also contains information about the workshop, such as titles and abstracts for the invited talks. For any question, you may contact YoungSetTheory2017@gmail.com.

With best regards,

The organisers

# Bohuslav Balcar (1943-2017)

With deep sorrow we inform that Dr. Bohuslav Balcar passed away on Friday, February 17th, 2017.

Bohuslav Balcar was born in 1943. In 1965 he finished his studies at the Charles University in Prague under the supervision of P. Vopěnka. Although he obtained a degree in numerical mathematics, his main interests were mathematical logic, automata theory, and set theory. He was one of the original members of the Prague set theory seminar founded by P. Vopěnka in 1962. Between 1965 and 1975 he was a member of several departments at the Faculty of Mathematics and Physics of the Charles University, and in 1975 he started working at ČKD Semiconductors. While employed at the `factory’ as he liked to call the company, he was awarded the Candidate of Sciences (PhD) degree for his work on the theory of semisets, participated in a section of the `national fundamental research plan’ directed by Z. Frolík, and published his most important results. Together with P. Simon he lead the Seminar on Reckoning at Charles University, participated and later organized the Winter Schools in Abstract Analysis and Prague Topological Symposia. In 1989 he was awarded the Doctor of Science degree and started working in the Institute of Mathematics of the Czech Academy of Sciences. Since 1992 he was a member of the the Institute for Advanced Studies, joint research institute of the Charles University and the Czech Academy of Sciences.

Bohuslav Balcar’s mathematical interests included set theory, Boolean algebras, topological dynamics, and logic foundations. He officially supervised five graduate students, and many more had earned their degree under or benefited from his unofficial supervision. His influence shaped several generations of Czech set theoreticians.

Bohuslav Balcar was a kind, inspirational, and unresentful man. He will be greatly missed.