5 papers
Imaginaries, products and the adele ring
Jamshid Derakhshan, Ehud Hrushovski
We describe the imaginary sorts of infinite products in terms of imaginary sorts of the factors. We extend the result to certain reduced powers and then to infinite products $\prod…
On first order amenability
Ehud Hrushovski, Krzysztof KrupiÅski, Anand Pillay
We introduce the notion of first order amenability, as a property of a first order theory : every complete type over , in possibly infinitely many variables, extends…
Model Equivalences
Michael Benedikt, Ehud Hrushovski
We look at equivalence relations on the set of models of a theory -- MERs, for short -- such that the class of equivalent pairs is itself an elementary class, in a language appropr…
Compactifications of pseudofinite and pseudo-amenable groups
Gabriel Conant, Ehud Hrushovski, Anand Pillay
We first give simplified and corrected accounts of some results in \cite{PiRCP} on compactifications of pseudofinite groups. For instance, we use a classical theorem of Turing \cit…
Specialization of Difference Equations and High Frobenius Powers
Yuval Dor, Ehud Hrushovski
We study valued fields equipped with an automorphism which is locally infinitely contracting in the sense that for all . We show that various notions of…