English

Quasi-Valuations Extending a Valuation

Commutative Algebra 2013-01-23 v1

Abstract

Suppose FF is a field with valuation vv and valuation ring OvO_{v}, EE is a finite field extension and ww is a quasi-valuation on EE extending vv. We study quasi-valuations on EE that extend vv; in particular, their corresponding rings and their prime spectrums. We prove that these ring extensions satisfy INC (incomparability), LO (lying over), and GD (going down) over OvO_{v}; in particular, they have the same Krull Dimension. We also prove that every such quasi-valuation is dominated by some valuation extending vv. Under the assumption that the value monoid of the quasi-valuation is a group we prove that these ring extensions satisfy GU (going up) over OvO_{v}, and a bound on the size of the prime spectrum is given. In addition, a 1:1 correspondence is obtained between exponential quasi-valuations and integrally closed quasi-valuation rings. Given RR, an algebra over OvO_{v}, we construct a quasi-valuation on RR; we also construct a quasi-valuation on ROvFR \otimes_{O_{v}} F which helps us prove our main Theorem. The main Theorem states that if RER \subseteq E satisfies RF=OvR \cap F=O_{v} and EE is the field of fractions of RR, then RR and vv induce a quasi-valuation ww on EE such that R=OwR=O_{w} and ww extends vv; thus RR satisfies the properties of a quasi-valuation ring.

Keywords

Cite

@article{arxiv.1209.4172,
  title  = {Quasi-Valuations Extending a Valuation},
  author = {Shai Sarussi},
  journal= {arXiv preprint arXiv:1209.4172},
  year   = {2013}
}

Comments

51 pages

R2 v1 2026-06-21T22:07:44.189Z