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#modeltheory — Public Fediverse posts

Live and recent posts from across the Fediverse tagged #modeltheory, aggregated by home.social.

  1. In the mountains, I love exploring nature and climbing any little hidden corner.

    My academic interests include mathematics (#mathematics) and mathematical logic ( #mathematicallogic #logic), particularly model theory ( #modeltheory), category theory ( #categorytheory), higher-order logic and metalogic ( #metalogic), as well as the philosophy of mathematics and logic ( #philosophyofmathematics #philosophyoflogic), epistemology and ontology of them.

    #introduction

  2. @LeoTsai14 While they do not actually call it so, set theoreticians do a lot of work in a category in which the objects are the models of set theory and the arrows are the elementary embeddings (en.wikipedia.org/wiki/Elementa) between them.
    Models of (ZFC-like) set theories have the interesting property that the maps between them are to some amount determined by the mappings between their classes of ordinals: If this map is an isomorphism, the whole map is one (en.wikipedia.org/wiki/Critical).
    You may also have a look at inner model theory (en.wikipedia.org/wiki/Inner_mo), I think.

    #SetTheory #ModelTheory #MathematicalLogic #Categories

  3. A new Ph.D thesis prize is being established in honor of Zoé Chatzidakis, by Fondation Sciences Mathématiques de Paris.

    This yearly award for an outstanding thesis in model theory will honor her scientific legacy and her commitment to the younger generation.

    helloasso.com/associations/fon

    #Math #ModelTheory #Logic

  4. Very excited about this new preprint, with Kyle Gannon and Krzysztof Krupinski!

    "Definable convolution and idempotent Keisler measures III. Generic stability, generic transitivity, and revised Newelski's conjecture"
    arxiv.org/abs/2406.00912

    Classical work by Wendel, Rudin, Cohen (before inventing forcing) and others classifies idempotent Borel measures on locally compact abelian groups, showing that they are precisely the Haar measures of compact subgroups.
    We are interested in a counterpart of this phenomenon in the definable category. In the same way as e.g. algebraic or Lie groups are important in algebraic or differential geometry, the understanding of groups definable in a given first-order structure (or in certain classes of first-order structures) is important for model theory and its applications. The class of stable groups is at the core of model theory, and the corresponding theory was developed in the 1970s-1980s borrowing many ideas from the study of algebraic groups over algebraically closed fields. More recently, many of the ideas of stable group theory were extended to the class of NIP groups, which contains both stable groups and groups definable in o-minimal structures or over the p-adics. This led to multiple applications, e.g. a resolution of Pillay’s conjecture for compact o-minimal groups, or Hrushovski’s work on approximate subgroups. This brought to light the importance of the study of invariant measures on definable subsets of the group, as well as the methods of topological dynamics. In particular, deep connections with tame dynamical systems as studied by Glasner, Megrelishvili and others have emerged.

    #Mathematics #ModelTheory #TopologicalDynamics

  5. After a short summer break exploring Scotland, it’s time to slowly get back into the saddle, giving a few talks, and preparing for the new academic year’s teaching.

    First up, a short visit to Bochum for a PhD exam, and an impromptu talk on non-classical models for the identity predicate.

    consequently.org/presentation/

    #logic #ModelTheory #ProofTheory #PhilosophicalLogic

  6. Survey of Animated Logical Graphs
    inquiryintoinquiry.com/2023/03

    This is a Survey of blog and wiki posts on Logical Graphs, encompassing several families of graph-theoretic structures originally developed by Charles S. Peirce as graphical formal languages or visual styles of syntax amenable to interpretation for logical applications.

    #Peirce #Logic #LogicalGraphs #EntitativeGraphs #ExistentialGraphs
    #Boole #BooleanAlgebra #BooleanFunctions #ModelTheory #ProofTheory
    #SpencerBrown #LawsOfForm #PropositionalCalculus #LogicAsSemiotics

  7. #LogicalGraphs • 14
    oeis.org/w/index.php?title=Log

    #Duality • Logical and Topological

    The procedure just described is called “traversing” the tree and the string read off is called the “#TraversalString” of the tree. The reverse operation of going from the string to the tree is called “parsing” the string and the tree constructed is called the “#ParseGraph” of the string.

    #Logic #Peirce #SpencerBrown #LawsOfForm
    #PropositionalCalculus #BooleanFunctions
    #GraphTheory #ModelTheory #ProofTheory

  8. The video of my yesterday's talk at the #IAS on some uses of #ModelTheory in #Erdős #Geometry is now online. (Please ignore the nonsense that I've said instead of the definition of modularity!)

    youtu.be/w5ITepQZL8U

  9. #LogicalGraphs • 3
    oeis.org/w/index.php?title=Log

    We begin on a low but expansive plateau of #FormalSystems #Peirce mapped out in his system of #AlphaGraphs \((\alpha),\) a platform so abstract in its mathematical forms as to support at least two interpretations for use in the conduct of logical reasoning. Along the way, we incorporate the later contributions of George #SpencerBrown, who revived and augmented Peirce's system in his book #LawsOfForm.

    #Logic #GraphTheory #ModelTheory #ProofTheory

  10. #LogicalGraphs • 1
    oeis.org/w/index.php?title=Log

    A #LogicalGraph is a graph-theoretic structure in one of the systems of graphical syntax Charles Sanders #Peirce developed for #Logic.

    In his papers on #QualitativeLogic, #EntitativeGraphs, and #ExistentialGraphs, Peirce developed several versions of a graphical formalism, or a graph-theoretic formal language, designed to be interpreted for logic.

    #PropositionalCalculus #BooleanFunctions
    #GraphTheory #ModelTheory #ProofTheory

  11. #LogicalGraphs • 3
    oeis.org/w/index.php?title=Log

    We begin on a low but expansive plateau of #FormalSystems #Peirce mapped out in his system of #AlphaGraphs \((\alpha),\) a platform so abstract in its mathematical forms as to support at least two interpretations for use in the conduct of logical reasoning. Along the way, we incorporate the later contributions of George #SpencerBrown, who revived and augmented Peirce's system in his book #LawsOfForm.

    #Logic #GraphTheory #ModelTheory #ProofTheory

  12. #LogicalGraphs • 3
    oeis.org/w/index.php?title=Log

    We begin on a low but expansive plateau of #FormalSystems #Peirce mapped out in his system of #AlphaGraphs \((\alpha),\) a platform so abstract in its mathematical forms as to support at least two interpretations for use in the conduct of logical reasoning. Along the way, we incorporate the later contributions of George #SpencerBrown, who revived and augmented Peirce's system in his book #LawsOfForm.

    #Logic #GraphTheory #ModelTheory #ProofTheory

  13. #LogicalGraphs • 3
    oeis.org/w/index.php?title=Log

    We begin on a low but expansive plateau of #FormalSystems #Peirce mapped out in his system of #AlphaGraphs \((\alpha),\) a platform so abstract in its mathematical forms as to support at least two interpretations for use in the conduct of logical reasoning. Along the way, we incorporate the later contributions of George #SpencerBrown, who revived and augmented Peirce's system in his book #LawsOfForm.

    #Logic #GraphTheory #ModelTheory #ProofTheory

  14. #LogicalGraphs • 3
    oeis.org/w/index.php?title=Log

    We begin on a low but expansive plateau of #FormalSystems #Peirce mapped out in his system of #AlphaGraphs \((\alpha),\) a platform so abstract in its mathematical forms as to support at least two interpretations for use in the conduct of logical reasoning. Along the way, we incorporate the later contributions of George #SpencerBrown, who revived and augmented Peirce's system in his book #LawsOfForm.

    #Logic #GraphTheory #ModelTheory #ProofTheory

  15. Hi! I am a philosopher and logician, and if you would like to understand the kind of work I do, the easiest way to get up to speed is to start with my little slip of a book “Proofs and Models in Philosophical Logic”. consequently.org/writing/pmpl-

    #introduction #philosophy #logic #prooftheory #modeltheory

  16. A workshop and a conference on #ModelTheory in Wroclaw, Poland this Fall!

    Model Theory Workshop: 15 - 18 September 2023
    math.uni.wroc.pl/~pkowa/regist

    Model Theory Conference: 19 - 23 September 2023
    math.uni.wroc.pl/~pkowa/regist

  17. #ModelTheory Conference in Seoul, in commemoration of Byunghan Kim’s 60th birthday.

    Aug. 28-30, 2023

    The registration deadline is June 15, 2023.
    This conference is ASL-sponsored, so students (who are ASL members) are eligible for ASL travel support. Partial travel expenses can also be provided to those who present a poster.

    sites.google.com/yonsei.ac.kr/

  18. Slides from my talk at the #ModelTheory Conference in celebration of Ludomir Newelski's 60th birthday in Będlewo, Poland. It's about recent work with Kyle Gannon on convolution semigroups of measures in NIP groups, which turn out to be particularly structured!

    math.ucla.edu/~chernikov/slide

  19. Now that my author copies of Logical Methods (written with @standefer) have arrived, I no longer have to worry about last-minute Christmas gift buying.

    If you order *your* copies from MIT Press (or wherever else you get your books), you won’t get them in time for Christmas. It’s released to the whole world on January 3.

    mitpress.mit.edu/9780262544849

    #logic #PhilLogic #ProofTheory #ModelTheory #Textbook

  20. All in another day’s work, talking about proofs and models in philosophical logic, this time focusing on boolean valuations, supervaluations, and tri-valuations.

    #PhilLogic #ModelTheory

  21. Intro to Mathematical Logic: from the basic first-order #logic, through #Gödel's Completeness, to the fundamentals of #ModelTheory! All in 28 videos from a course I've taught at #UCLA:

    youtube.com/playlist?list=PL54