Sebastien Vasey

Sebastien Vasey

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

Writings

Research papers

  1. 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.

  2. 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).
  3. TLDR: An abstract elementary class can have at most one forking-like notion.

  4. 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.

  5. 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).

  6. 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.

Various

About Me

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.

Teaching

Talks

Various