Note: If you are looking for continuous model theory notes from the version of Math 712 taught in the fall of 2012, they can be found here

Applications of model theory
Math 712

The class will meet Tuesdays and Thursday from 12:00 - 1:20 beginning Jan. 9.  The course will roughly follow the outline below.  There will be 5 assignments and in addition, each student will make a presentation on a topic of their choice related to the course material. Slides, reference material and other relevant links will appear on this page.

Course Outline

Week 1 - 2, Jan. 9 - 18: A basic introduction to model theory including a discussion of language, structure and ultraproducts. We will look at both classical and continuous model theory with an eye to the applications in the course.

References: 
Classical model theory
  • D. Marker, Model theory: an introduction, Springer Graduate Text in Mathematics, 217, 2002.
  • K. Tent and M. Ziegler, A course in model theory, Cambridge University Press, 2012.

Continuous model theory

  • I. Ben Yaacov, A. Berenstein, C. W. Henson, and A. Usvyatsov. Model theory for metric structures. In Z. Chatzidakis et al, editor, Model Theory with Applications to Algebra and Analysis, Vol. II, number 350 in London Math. Soc. Lecture Notes Series, pages 315–427. Cambridge University Press, 2008.
  • B. Hart, An introduction to continuous model theory, in I. Goldbring, editor, Model theory of operator algebras, DeGruyter series on Logic and its applications, 2023.
Assignment 1 due in class on Jan. 30; here are solutions.

Week 3 - 4, Jan. 23 - Feb. 1: The random graph and the Urysohn sphere.  These two structures are examples of Fraisse construction in the classical and continuous settings respectively.  We will look at axiomatizations of both structures and probabilistic results which arise.
Assignment 2 due by email in pdf format (no pictures please) on Feb. 13; here are solutions.

Week 5 - 6, Feb. 6 - Feb. 15: The Szemeredi regularity lemma and applications in additive combinatorics.  Szemeredi proved his famous lemma in the interest of finding long arithmetic progressions in sets of natural numbers with positive density.  The regularity lemma has many proofs and we will look at a particularly simple one arising from model theoretic considerations.

Assignment 3 due by email in pdf format (no pictures please) on Mar. 12

Here is the complete details of the necessary integral argument in the regularity lemma.
Week 7 - 8, Feb. 27 - Mar. 7: The model theory of finite fields.  James Ax initiated the model theory of the class of finite fields in the late 1960's.  He provided an axiomatization of what are called pseudo-finite fields.  We will look at this theory with an eye toward quantifier simplification and decidability.
  • J. Ax, The Elementary Theory of Finite Fields, Annals of Mathematics, 88 (2), 1968, pp. 239-271. This can be found on jstor.
  • Z. Chatzidakis, various notes on finite fields; I was mostly looking at her Helsinki notes.
  • Z. Chatzidakis, L. van den Dries and A. Macintrye, Definable sets in finite fields, J. reine angew. Math. 427 (1992), 107-135.
Week 9 - 10, Mar. 12 - Mar. 21: The model theory of matrix algebras and its relationship to quantum complexity and decidability in the continuous setting.

Week 11 - 12, Mar. 26 - Apr. 9: In-class presentations and other topics as time permits.
Assignment 4 due by email in pdf format (no pictures please) on Apr. 25