21-600 Mathematical Logic I Instructor: Peter Andrews MWF 11:30am-12:20pm HH B103 12 Units Description: The study of formal logical systems which model the reasoning of mathematics, scientific disciplines, and everyday discourse. Propositional calculus and first-order logic. Syntax, axiomatic treatment, derived rules of inference, proof techniques, computer-assisted formal proofs, normal forms, consistency, independence, semantics, soundness, completeness, the Lowenheim-Skolem and Downward Lowenheim-Skolem Theorems, compactness. TEXTBOOK: Peter B. Andrews, An Introduction to Mathematical Logic and Type Theory: To Truth Through Proof, Second Edition, Kluwer Academic Publishers, now published by Springer, 2002. 21-602 Set Theory I Instructor: Ernest Schimmerling MW 3:30-4:50 Porter Hall A19D 12 Units Description: First semester graduate level set theory. Godel proved that if ZF is consistent, then so is ZFC + GCH; this is the most important theorem that will be covered in the course. The main topics are ZFC, cardinal arithmetic, the rank hierarchy, the H(kappa) hierarchy, the reflection theorem, absoluteness theorems, relative consistency, infinitary combinatorics (diamond principles, Aronszajn and Suslin trees, etc.), the model HOD, the constructible universe, and descriptive set theory. TEXTBOOK OR REFERENCES: Kenneth Kunen, "Set theory : An introduction to independence proofs" 21-603 Model Theory I Instructor: Rami Grossberg (rami@cmu.edu) MWF 1:30 Room TBA 12 Units DESCRIPTION: Model theory is one of the four major branches of mathematical logic. There are many applications of model theory to algebra (e.g. field theory, algebraic geometry, number theory, and group theory), analysis (non-standard analysis, complex manifolds and the geometry of Banach spaces) and theoretical computer science (via finite model theory) as well as set theoretic topology and set theory. This course is the first in a sequence. The purpose of this course to introduce the student to some of the most important ideas of the field with a special attention to "classification theory" which is the most important subfield of modern model theory. The main focus of the course is Morely's categoricity theorem, the related conceptual infrastructure and extensions. Topics will include: compactness theorem, model completeness, elementary decideability results, Henkin's omitting types theorem, prime models. Elementary chains of models, some basic two-cardinal theorems, saturated models (characterization and existence), basic results on countable models including Ryll-Nardzewski's theorem. Indiscernible sequences, and connections with Ramsey theory, Ehrenfeucht-Mostowski models. Introduction to stability (including the equivalence of the order-property to instability), chain conditions in group theory corresponding to stability/superstablity/omega-stability, strongly minimal sets, various rank functions, primary models, and a proof of Morley's categoricity theorem. Basic facts about infinitary languages and abstract elementary classes, computation of Hanf-Morley numbers. PREREQUISITE: This is a graduate level course, while at the beginning the pace will be slow, the pace will speed up in the second half. In the past many students where undergraduates, so the prerequisites are kept to the minimum of "an undergraduate-level" course in logic. Motivated undergraduate students are encouraged to contact the instructor. TEXT: Rami Grossberg, A course in model theory, a book in preparation. Most of the material (and more) appears in the following books: 1. C. C. Chang and H. J. Keisler, Model Theory, North-Holland 1990. 2. Bruno Poizat, A course in Model Theory, Springer-Verlag 2000. 3. S. Shelah, Classification Theory, North-Holland 1991. I will not use a text, but will provide access to my notes on a weekly basis. EVALUATION: Will be based on weekly homework assignments (20%), a 50 minutes midterm (20%) and a 3 hours in-class comprehensive final written examination (60%). COURSE WEBPAGE: www.math.cmu.edu/~rami/mt1.10.desc.html 80-413/713 Category Theory Instructor: Steve Awodey TR 1:30 - 2:50PM PH A22 12 units Description: Category theory, a branch of abstract algebra, has found many applications in mathematics, logic, and computer science. Like such fields as elementary logic and set theory, category theory provides a basic conceptual apparatus and a collection of formal methods useful for addressing certain kinds of commonly occurring formal and informal problems, particularly those involving structural and functional considerations. This course is intended to acquaint students with these methods, and also to encourage them to reflect on the interrelations between category theory and the other basic formal disciplines.A text will be provided. Prerequisites: one course in logic or algebra. 80-414/714 COMPUTABILITY: Machines & Minds Instructor: Wilfried Sieg W 2:00am-4:20pm BH 150 10-12 Units Description: This deeply interdisciplinary seminar is divided into three parts. Part 1 reviews the emergence of the central concept and arguments for Churchıs or Turingıs Thesis; it presents then, in sharp contrast, an axiomatic characterization of serial and parallel computability. Part 2 takes up the considerations of Gödel and Turing to relate machines and the human mind, in particular, with respect to mathematics. Finally, Part 3 discusses the use of computations in cognitive psychology to model aspects of human minds; the focus is on (Post-) production systems and parallel-distributed processes. 21-800 Advanced topics in Logic: large cardinals and inner models I Instructor: Ernest Schimmerling MWF 2:30 Porter Hall 226B 12 Units Topics: The hierarchy of large cardinal axioms; the fine structure of the constructible universe; the beginnings of core model theory; applications. This is the first part of a two semester series that will eventually reach the level of inner model theory where iteration trees play a key role. Prerequisites: Students who have not taken 21-602 or the equivalent would need to take both simultaneously and stay ahead in 21-602 with the help of the instructor. Such plans would need to be discussed before the semester begins at the earliest possible date. 80-813 Seminar in the Philosophy of Mathematics Instructors: Jeremy Avigad (Carnegie Mellon) and Kenneth Manders (University of Pittsburgh) F 10-12:30 BH 150 (at CMU) and 1001-B Cathedral of Learning (at Pitt) 12 units Algebra and number theory in the nineteenth century A number of questions regarding the types of equations that can be solved in the integers and in the reals have their origins in antiquity, when mathematics was held to be the science of quantity, both continuous (magnitude) and discrete (number). The beginning of the nineteenth century brought striking advances along these lines. For example, Gauss gave a detailed analysis of the integers that can be represented by a given quadratic form, and Abel and Galois showed that the general quintic equation has no solution by radicals. A good deal of effort in the nineteenth century was devoted to making sense of these results, and by the end of the century the ideas had been recast in algebraic structural terms. Galois theory and the study of quadratic forms are now invariably presented in terms of field extensions and their properties. This shift is prototypical of the transition to the "modern" view of mathematics. In this seminar, we will trace the development of these ideas. We will focus, as much as possible, on the original sources, with an eye towards obtaining a better understanding of the methodological considerations that drove these developments.