Logic & Philosophy of Science Colloquium


Gunnar Wilken
  Ohio State University

"Ordinals and Substructures"


The notion of $\Sigma_n$-elementary substructure over simple languages on the ordinals allows for powerful applications in proof theory and
leads to a general approach in the theory of ordinal numbers.

I will illustrate this by sketching the consistency of Reinhardt's Strong Mechanistic Thesis with Epistemic Arithmetic (due to T. Carlson), then briefly
showing how independence results can be obtained, and finally giving some heuristics for ordinal notation systems which arise in a new type of proof theoretic analyses.

Friday, September 29, 2006
SST 777
3 pm

Refreshments will be served