
Pavel Hrubes

(Institute of Mathematics)

An interesting (?) problem equivalent to Continuum Hypothesis
 Abstract:

I will discuss a problem which came up in the context of machine learning, and which ended up being undecidable in ZFC. The flavor is similar to the socalled Axioms of Symmetry of Freiling. Based on a work with B. ShaiDavid, S. Moran, A. Shpilka, A. Yehudayoff.

Emil Jerabek

(Institute of Mathematics)

Rigid models of Presburger arithmetic
 Abstract:

While all firstorder theories have plenty of models with many automorphisms (e.g., saturated), models with few automorphisms are harder to come by, and their existence varies with the theory. In the extreme case of rigid models (= with no nontrivial automorphism), some theories have no rigid models at all (such as divisible ordered abelian groups), while e.g. Peano arithmetic has many: every model of PA has a rigid elementary endextension of the same cardinality.
In this talk, we will give a complete description of rigid models of Presburger arithmetic Th(Z,+,
Pavel Pudlak, Neil Thapen
organizers