Universität Bonn

Trimester Program: "Universality and Homogeneity"


September 2 - December 20, 2013

Organizers: Alexander Kechris, Katrin Tent, Anatoly Vershik

Description: The goal of the program was to study and link universality phenomena in different areas of pure mathematics. These areas included model theory, combinatorics, descriptive set theory, group theory, dynamical systems, especially ergodic theory and topological dynamics, random matrices and representation theory. In this way we promoted interactions in an unprecedented way between these different areas.

Universality is a pervasive notion in mathematics, and is suggestive of useful analogies between different areas. Examples are Fraïssé theory in logic, universal graphs in combinatorics, the universal Urysohn space in topology, universality in algebraic geometry, and so on. We considered it important to initiate a discussion of universality as a global phenomenon in mathematics, and brought together some of the main contributors.

The main reason for studying universal objects is that they may act as a frame of reference for what kind of results to expect, what kind of objects might exist and how homogeneous certain structures are. If a class of structures allows universal objects, studying these objects yields important insights into the class of structures and on individual structures of this class. Universal objects often serve both as examples for and counterexamples to theorems and conjectures. They are typically very homogeneous and reflect all properties that may or may not be realized. Model theory provides techniques for constructing and studying such objects. Also constructing a structure by a 'random' process often leads to the universal object of a certain class. Therefore, we obtained feedback in both directions from the universal object to random processes and conversely.

Associated Events: 

  • Trimester Seminar
  • Mini Courses
  • Workshop on Homogeneous Structures
  • Special Seminar on Universality of moduli spaces and geometry
TP_2013_09.jpg
The Apostles Peter and Paul Domenikos Theotokopoulos (El Greco) 1587-92. Printed by permission of The State Hermitage Museum, St. Petersburg, Russia © Wikimedia Commons

Publications

No. Author(s) Title Preprint Publication
2013c01 Zalesski, A. E. On the Steinberg character of an orthogonal group over a finite field 1310.4440 J. Algebra Appl. 13(7) (2014), 46.
https://doi.org/10.1142/S0219498814500339
2013c02 Wesolek, P. Conjugacy class conditions in locally compact second countable groups 1310.1561 Proc. Amer. Math. Soc. 144(1) (2016), 399–409.
https://doi.org/10.1090/proc/12645
2013c03 Mildenberger, H. Finitely many near-coherence classes of ultrafilters 1404.7350  
2013c04 Garbulińska-Wȩgrzyn, J.; Kubiś, W. A universal operator on the Gurariĭ space 1310.2380 J. Operator Theory. 73(1) (2015), 143–158.
https://doi.org/10.7900/jot.2013oct09.1999
2013c05 Jasiński, J.; Laflamme, C.; Nguyen Van Thé, L.; Woodrow, R. Ramsey precompact expansions of homogeneous directed graphs 1310.6466 Electron. J. Combin. 21(4) (2014), 31.
https://doi.org/10.37236/3840
2013c06 Bogachev, L. V. Unified derivation of the limit shape for multiplicative ensembles of random integer partitions with equiweighted parts 1111.3311 Random Structures Algorithms. 47(2) (2015), 227–266.
https://doi.org/10.1002/rsa.20540
2013c07 Evans, D. M.; Tsankov, T. Free actions of free groups on countable structures and property (T) 1312.5140 Fund. Math. 232(1) (2016), 49–63.
https://doi.org/10.4064/fm232-1-4
2013c08 Sabok, M. Automatic continuity for isometry groups 1312.5141 J. Inst. Math. Jussieu. 18(3) (2019), 561–590.
https://doi.org/10.1017/s1474748017000135
2013c09 Vershik, A. M. Intrinsic metric on graded graphs, standardness, and invariant measures 1312.7239 J. Math. Sci. (transl.). 200(6) (2014), 677–681.
https://doi.org/10.1007/s10958-014-1958-0
2013c10 Bartošová, D.; Kwiatkowska, A. Lelek fan from a projective Fraïssé limit 1312.7514 Fund. Math. 231(1) (2015), 57–79.
https://doi.org/10.4064/fm231-1-4
2013c11 Ben Yaacov, I.; Tsankov, T. Weakly almost periodic functions, model-theoretic stability, and minimality of topological groups 1312.7757 Trans. Amer. Math. Soc. 368(11) (2016), 8267–8294.
https://doi.org/10.1090/tran/6883
2013c12 Bodirsky, M.; Pinsker, M.; Pongrácz, A. Reconstructing the topology of clones 1312.7699 Trans. Amer. Math. Soc. 369(5) (2017), 3707–3740.
https://doi.org/10.1090/tran/6937
2013c13 Doucha, M. Metrically universal abelian groups 1312.7683 Trans. Amer. Math. Soc. 369(8) (2017), 5981–5998.
https://doi.org/10.1090/tran/7059
2013c14 Hubička, J.; Nešetřil, J. Bowtie-free graphs have a Ramsey lift 1402.2700  Advances in Applied Mathematics. 96 (2018), 286-311.
https://doi.org/10.1016/j.aam.2017.12.005
2013c15 Fiala, J.; Hubička, J.; Long, Y. Universality of intervals of line graph order 1402.3736 European J. Combin. 41 (2014), 221–231.
https://doi.org/10.1016/j.ejc.2014.04.008
2013c16 Bogachev, L. V. Limit shape of random convex polygonal lines: even more universality 1111.3529 J. Combin. Theory Ser. A. 127 (2014), 353–399.
https://doi.org/10.1016/j.jcta.2014.07.005
2013c17 Doucha, M. Non-abelian group structure on the Urysohn universal space 1403.3277 Fund. Math. 228(3) (2015), 251–263.
https://doi.org/10.4064/fm228-3-3
2013c18 Melleray, J.; Nguyen Van Thé, L.; Tsankov, T. Polish groups with metrizable universal minimal flows 1404.6167 Int. Math. Res. Not. IMRN. (5) (2016), 1285–1307.
https://doi.org/10.1093/imrn/rnv171
2013c19 Ben Yaacov, I.; Kaïchouh, A. Reconstruction of separably categorical metric structures 1405.4177 J. Symb. Log. 81(1) (2016), 216–224.
https://doi.org/10.1017/jsl.2014.80
2013c20 Cherlin, G. Henson graphs and Urysohn-Henson graphs as Cayley graphs pdf Funct. Anal. Appl. 49(3) (2015), 189–200.
https://doi.org/10.1007/s10688-015-0103-2
2013c21 Koshevoy, G. Cluster monomials in ℂ[GLn/N], a simplicial fan in the cone of semi-standard Young tableaux, and the Lusztig basis 1411.3569  
2013c22 Grigoryev, D.; Koshevoy, G. Complexity of tropical Schur polynomials pdf J. Symbolic Comput. 74 (2016), 46–54.
https://doi.org/10.1016/j.jsc.2015.05.005
2013c23 Ben Yaacov, I.; Henson, C. W. Generic orbits and type isolation in the Gurarij space 1211.4814 Fund. Math. 237(1) (2017), 47–82.
https://doi.org/10.4064/fm193-3-2016
2013c24 Vershik, A. The problem of describing central measures on the path spaces of graded graphs 1408.3291 Funct. Anal. Appl (transl.).48(4) (2014), 256–271.
https://doi.org/10.1007/s10688-014-0069-5
2013c25 Towsner, H. σ-algebras for quasirandom hypergraphs 1312.4882 Random Structures Algorithms. 50(1) (2017), 114–139.
https://doi.org/10.1002/rsa.20641
2013c26 Ackerman, N.; Freer, C.; Nešetřil, J.; Patel, R. Invariant measures via inverse limits of finite structures 1310.8147 European J. Combin. 52 (2016), 248–289.
https://doi.org/10.1016/j.ejc.2015.07.006
2013c27 Ackerman, N.; Freer, C.; Kwiatkowska, A.; Patel, R. A classification of orbits admitting a unique invariant measure 1412.2735 Ann. Pure Appl. Logic. 168(1) (2017), 19–36.
https://doi.org/10.1016/j.apal.2016.08.003
2013c28 Mwesigye, F.; Truss, J. K. Finitely coloured ordinals pdf  
2013c29 Glasner, E. RP[d] is an equivalence relation: An enveloping semigroup proof 1402.3135  
2013c30 Glasner, E.; Megrelishvili, M. Eventual nonsensitivity and tame dynamical systems 1405.2588  
2013c31 Ben Yaacov, I.; Ibarlucía, T.; Tsankov, T. Eberlein oligomorphic groups 1602.05097 Trans. Amer. Math. Soc. 370(3) (2018), 2181–2209.
https://doi.org/10.1090/tran/7227
2013c32 Henson, C. W.; Raynaud, Y. Asymptotically Hilbertian modular Banach spaces: examples of uncountable categoricity 1606.03122 Comment. Math. 56(1) (2016), 119–144.
https://doi.org/10.14708/cm.v56i1.1231
2013c33 Evans, D. M.; Ghadernezhad, Z.; Tent, K. Simplicity of the automorphism groups of some Hrushovski constructions 1312.3430 Ann. Pure Appl. Logic. 167(1) (2016), 22–48.
https://doi.org/10.1016/j.apal.2015.09.002
2013c34 Glasner, E.; Gutman, Y.; Ye, X. Higher order regionally proximal equivalence relations for general minimal group actions 1706.07227 Adv. Math. 333 (2018), 1004–1041.
https://doi.org/10.1016/j.aim.2018.05.023

Participants

Name Affiliation
Andrey Alpeev Saint-Petersburg State University
Dana Bartosova University of Sao Paolo
Oleg Belegradek Istanbul Bilgi University
Itaï Ben Yaacov Université Claude Bernard Lyon 1
Manuel Bodirsky CNRS / LIX, Ecole Polytechnique
Leonid Bogachev University of Leeds
Gregory Cherlin Rutgers University
Michal Doucha Polish Academy of Sciences
David Evans University of East Anglia
Valentin Ferenczi Universidade de São Paulo
Cameron Freer Massachusetts Institute of Technology (MIT)
Pavel Galashin Saint-Petersburg State University
Zaniar Ghadernezhad Westfälische Wilhelms-Universität Münster
Moshe Shmuel Glasner Tel Aviv University
Dmitry Grigoryev Université Lille 1
Yonatan Gutman University of Cambridge
C. Ward Henson University of Illinois
Jan Hubicka Charles University in Prague
Tomás Ibarlucía Université Claude Bernard Lyon 1
Itay Kaplan Universität Münster
Michael Kapovich University of California
Adriane Kaïchouh Université Claude Bernard - Lyon 1
Ulrich Kohlenbach TU Darmstadt
Gleb Koshevoy CEMI RAS
Wieslaw Kubis Academy of Sciences of the Czech Republic
Aleksandra Kwiatkowska Universität Bonn
Claude Laflamme University of Calgary
Stéphane Laurent Université de Strasbourg
Julie Linman University of Colorado at Boulder
Yangjing Long Max Planck Institute for Mathematics in the Sciences
László Lovász Eötvös Loránd University
Hugh Dugald Macpherson University of Leeds
Barnaby Martin  
Julien Melleray Université Lyon 1
Heike Mildenberger Albrecht-Ludwigs-Universität Freiburg
Benjamin D. Miller Universität Münster
Jaroslav Nesetril Charles University in Prague
Lionel Nguyen Van Thé Université d'Aix-Marseille
Piotr Niemiec Jagiellonian University
Andre Nies University of Auckland
Javier de la Nuez Gonzalez WWU Münster
Alexey Ostrovskiy Universität der Bundeswehr München
Daniel Palacín Universität Münster
Rehana Patel Olin College of Engineering
Fedor Petrov Steklov Mathematical Institute RAS
Michael Pinsker Technische Universität Wien
András Pongrácz Laboratoire d'Informatique de l'École Polytechnique
Yves Raynaud UPMC
Matatyahu Rubin Ben Gurion University
Rizos Sklinos Universität Münster
Miodrag Sokic California Institute of Technology
Slawomir Solecki University of Illinois
Katrin Tent Universität Münster
Stevo Todorcevic University of Toronto
Henry Towsner University of Pennsylvania
John Truss University of Leeds
Todor Tsankov Université Paris Diderot
Slawomir Turek Uniwersytet Jana Kochanowskiego w Kielcach
Anatoly Vershik St. Petersburg Department of Steklov Institute of Mathematics
Dimitris Vlitas University of Athens
Phillip Wesolek University of Illinois at Chicago
Jay Williams Caltech
Joshua Wiscons Universität Münster
Alexandre Zalesski University of East Anglia
Boris Zilber University of Oxford

This list does not include people who only participated in workshops.

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