On pythagorean real irreducible algebroid curves

In this note we deal with the pythagoras number p of certain 1-dimensional rings, i.e., real irreducible algebroid curves over a real closed ground field k. The problem we are concerned with is to characterize those real irreducible algebroid curves which are pythagorean (i.e., p = 1). We obtain two...

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Bibliographic Details
Author: Ruiz Sancho, Jesús María
Format: article
Publication Date:1984
Country:España
Institution:Universidad Complutense de Madrid (UCM)
Repository:Docta Complutense
Language:English
OAI Identifier:oai:docta.ucm.es:20.500.14352/64761
Online Access:https://hdl.handle.net/20.500.14352/64761
Access Level:Open access
Keyword:512.7
Real irreducible algebroid curve
Pythagoras number
sum of squares
low multiplicity
Geometria algebraica
1201.01 Geometría Algebraica
Description
Summary:In this note we deal with the pythagoras number p of certain 1-dimensional rings, i.e., real irreducible algebroid curves over a real closed ground field k. The problem we are concerned with is to characterize those real irreducible algebroid curves which are pythagorean (i.e., p = 1). We obtain two theorems involving the value-semigroup. Then we apply them to solve the cases of: (a) Gorenstein curves, (b) planar curves, (c) monomial curves, and (d) curves of multiplicity <= 5. Finally, two conjectures are stated.