On a theorem by de Felipe and Teissier about the comparison of two henselisations in the non-noetherian case

TL;DR

This paper provides a simplified, algebraic, and constructive proof of a theorem comparing two henselisations in non-noetherian local domains, extending the original results by de Felipe and Teissier.

Contribution

It offers a new, algebraic, and constructive proof of the comparison theorem, along with a slight generalization of the original result.

Findings

Simplified algebraic proof of the theorem

Constructive approach enabling generalization

Extension of the original theorem to broader cases

Abstract

Let R be a local domain, v a valuation of its quotient field centred in R at its maximal ideal. We investigate the relationship between R^h, the henselisation of R as local ring, and {\~v}, the henselisation of the valuation v, by focussing on the recent result by de Felipe and Teissier referred to in the title. We give a new proof that simplifies the original one by using purely algebraic arguments. This proof is moreover constructive in the sense of Bishop and previous work of the authors, and allows us to obtain as a by-product a (slight) generalisation of the theorem by de Felipe and Teissier.