English

Definable retractions over Henselian valued fields with analytic structure

Algebraic Geometry 2019-02-01 v2

Abstract

Let KK be a Henselian, non-trivially valued field with separated analytic structure. We prove the existence of definable retractions onto an arbitrary closed definable subset of KnK^{n}. Hence directly follow definable non-Archimedean versions of the extension theorems by Tietze--Urysohn and Dugundji. This generalizes our previous paper dealing with complete non-Archimedean fields with separated power series and remains true for Henselian valued fields with strictly convergent analytic structure, because every such a structure can be extended in a definitional way to a separated analytic structure. Our proof uses a variant of the one from that paper, based on canonical resolution of singularities, and a model-theoretic compactness argument.

Keywords

Cite

@article{arxiv.1901.09922,
  title  = {Definable retractions over Henselian valued fields with analytic structure},
  author = {Krzysztof Jan Nowak},
  journal= {arXiv preprint arXiv:1901.09922},
  year   = {2019}
}

Comments

arXiv admin note: text overlap with arXiv:1901.00162 Withdrawn because of an essential gap in the model-theoretic compactness argument, which requires a deeper analysis of canonical desingularization from the viewpoint of definability

R2 v1 2026-06-23T07:24:38.204Z