https://huji.zoom.us/j/83455450944?pwd=xV1VbzZQLGWvkF9pg0gcmJSqvrfP2a.1
Meeting ID: 834 5545 0944
Passcode: 901314
Title: Ax-Kochen/Ershov principles in positive characteristic
Abstract: A major open problem in the model theory of valued fields is
to gain an understanding of the first-order theory of the power series
field F((t)), where F denotes a finite field. For sufficiently "nice"
henselian valued fields, the Ax-Kochen/Ershov philosophy allows to
reduce questions of elementary equivalence and elementary embeddings to
the analogous questions about the value group and residue field (or
related structures). In my talk, I will present a new such principle
which applies in particular to a large class of algebraic extensions of
F((t)), albeit not to F((t)) itself. The talk is based on joint work
with Konstantinos Kartas and Jonas van der Schaaf.