Department of Mathematical Sciences

Carnegie Mellon University

Pittsburgh, PA 15213

Office: Wean Hall 7108

Email: `sebv (at) cmu (dot) edu`

Writings | About Me | Teaching | Talks | Various

Sebastien Vasey,

*Indiscernible extraction and Morley sequences*, Accepted (June 9, 2014), Notre Dame Journal of Formal Logic. Preprint: pdf arXiv, 6 pages. Last updated on June 4, 2014 (see previous versions, including one with more background).TLDR: In simple theories, Morley sequences can be built using only Ramsey's theorem and compactness.

- Will Boney, Rami Grossberg, Alexei Kolesnikov, and Sebastien Vasey,
*Canonical forking in AECs*, Submitted. Preprint: pdf arXiv, 31 pages. Last updated on April 5, 2014 (see previous versions). Sebastien Vasey,

*Forking and superstability in tame AECs*, Submitted. Preprint: pdf arXiv, 30 pages. Last updated on June 30, 2014 (see previous versions).TLDR: Any tame abstract elementary class categorical in a suitable cardinal admits a forking-like notion for 1-types. It follows for example that tameness and categoricity at a cardinal of high-enough cofinality imply stability everywhere.

Will Boney and Sebastien Vasey,

*Tameness and frames revisited*, Submitted. Preprint: pdf arXiv, 31 pages. Last updated on August 28, 2014 (see previous versions).TLDR: Tameness in a good frame implies that the good frame transfers up and that a well-behaved notion of dimension can be defined (any two maximal infinite independent sets have the same cardinality).

Sebastien Vasey,

*Infinitary stability theory*, In preparation. Draft: pdf arXiv, 93 pages. Last updated on December 10, 2014 (see previous versions).TLDR: We introduce the Galois Morleyization of an AEC: a trick to think of semantic (Galois) types as being syntactic. We use this to prove several stability-theoretic results in fully tame and type short AECs, culminating in the construction of a global independence notion from categoricity.

TLDR: An abstract elementary class can have at most one forking-like notion.

- Synthesis for Rational Linear Arithmetic: My Bachelor thesis (2011) on automated program generation.
- Lecture notes for 21-127 Concepts of mathematics based on a course I taught in Summer 2014. The source is available. Here are the solutions to every assignments.

I am a math graduate student at Carnegie Mellon University (CMU). I started my Ph.D. in the Fall of 2012. Before that, I was studying Communication Systems and Computer Science at the Ecole Polytechnique Fédérale de Lausanne (EPFL).

My encounter with mathematical logic in 2010, and an exchange year at CMU in 2011-12 made me decide to change fields and turn to pure mathematics. I still hold a B.A. in Communication Systems from EPFL.

I am interested in pure model theory, and its interaction with algebra and combinatorial set theory. My advisor is Rami Grossberg.

From the beginning of Fall 2014 to the end of Fall 2015, I am supported by a Doc.Mobility fellowship from the Swiss National Science Foundation.

- In Spring 2012, I was the grader for 21-329 Set Theory.
- In Fall 2012, I was a teaching assistant for 21-120 Differential and Integral Calculus.
- In Spring 2013, I was a teaching assistant for 21-127 Concepts of Mathematics.
- In Fall 2013, I was (once again) a teaching assistant for 21-120 Differential and Integral Calculus.
- In Fall 2013, I was also grading for 21-300 Basic Logic.
- In Summer 2014 (session one), I was the instructor for 21-127 Concepts of Mathematics.

- Independence in tame abstract elementary classes: Talk given at the 2015 JMM (Special session on beyond first order model theory) in San Antonio on Jan. 11, 2015.
- Infinitary stability theory: Talk given at a miniconference (before the 2015 JMM) at the University of Texas at San Antonio on Jan. 9, 2015.
- Independence in tame abstract elementary classes: Talk given at the logic seminar at the University of Maryland on Nov. 11, 2014.
- Independence in tame abstract elementary classes: Talk given at the model theory seminar at the City University of New York on Oct. 31, 2014.
- Infinitary stability theory: Seven-parts talk given at the CMU model theory seminar (from Oct. 13, 2014 to Dec. 1, 2014).
- Schanuel's conjecture and excellence: Talk given at the CMU graduate student seminar on Sep. 30, 2014.
- Forking and superstability in tame abstract elementary classes: Talk given at the Classification Theory Workshop in NIMS (Daejeon, South Korea) on Aug. 9, 2014.
- Indiscernible extraction and Morley sequences: Talk given at the 2014 Logic Colloquium (Vienna University of Technology) on Jul. 19, 2014.
- Indiscernible extraction and Morley sequences: Talk given at the 15th Annual Graduate Student Conference in Logic (University of Wisconsin - Madison) on Apr. 27, 2014.
- O-minimality: Talk given at the CMU Graduate Student Seminar on Feb. 19, 2014.
- Existence of Morley sequences in simple theories: Two-parts talk given at the CMU Model Theory Seminar on Feb. 10, 17, 2014.
- Quasiminimal Structures and Excellence: Three-parts talk given at the CMU Model Theory Seminar on Oct. 14, 21, 28, 2013.
- Using the Axiom of Choice to Predict the Future: Talk given at the CMU Graduate Student Seminar on Jan. 17, 2013.
- Counting to Infinity and Beyond: Talk given to undergraduates at the CMU Math Club on Sep. 26, 2012.

- Privacy is like air: you never notice it exists, but you need it. I encourage you to use my PGP key
*(last updated: Sep. 21, 2013)*. - Here is a list of the classes I have taken / am taking at CMU.
- As everybody should know, all mathematicians are programmers, and conversely. Here are some of my programs .
- My old homepage: archived here since Feb. 10, 2013. Not maintained anymore.
- Like every other webpage, this webpage is under construction!