Hostname: page-component-586b7cd67f-2brh9 Total loading time: 0 Render date: 2024-11-24T18:52:54.878Z Has data issue: false hasContentIssue false

Some Local-Global Principles for Formally Real Fields

Published online by Cambridge University Press:  20 November 2018

M. Marshall*
Affiliation:
University of Saskatchewan, Saskatoon, Saskatchewan
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

Let F be a formally real field, and let A be a preordering of F; that is, a subset of F satisfying Δ + Δ = Δ, Δ Δ = Δ, F2 ⊆ Δ. Denote by X Δ the set of all orderings P of F satisfying P ⊇ Δ. Thus Δ = ⋂ pxΔP. This result is well known. It was first proved by Artin [3, Satz 1] in the case Δ = ∑ F2.

Type
Research Article
Copyright
Copyright © Canadian Mathematical Society 1977

References

1. Arason, J. K., Primideale im graduierten Wittring und im mod 2-Cohomologiering, Math. Zeit. 14S (1975), 139143.Google Scholar
2. Arason, J. and Pfister, A., Beweis des Krullschen Durchschnittsatzes fur den Wittring, Invent. Math. 12 (1971), 173176.Google Scholar
3. Artin, E., Uber die Zerlegung definiter Funktionen in Quadrate, Hamb. Abh. 5 (1927), 100115.Google Scholar
4. Becker, E. und Kôpping, Eberhard, Reduzierte quadratische Formen und Semiordnungen reeller Korper, to appear, Abh. Math. Sem. Univ. Hamburg 46.Google Scholar
5. Brôcker, L., Zur théorie der quadratischen formen uber formal reellen korper, Math. Annalen 210 (1974), 233256.Google Scholar
6. Elman, R. and Lam, T. Y., Pfister forms and K-theory of fields, J. of Algebra 23 (1972), 181213.Google Scholar
7. Elman, R. and Lam, T. Y. Quadratic forms over formally real fields and pythagorian fields, Amer. J. Math. 94 (1972), 11551194.Google Scholar
8. Elman, R. and Lam, T. Y. Quadratic forms and the u-invariant I, Math. Zeit. 131 (1972), 283304.Google Scholar
9. Elman, R. and Lam, T. Y. Classification theorems for quadratic forms over fields, Commentarii Math. Helvetici, 49 (1974), 373381.Google Scholar
10. Marshall, M., A reduced theory of quadratic forms, unpublished notes.Google Scholar
11. Milnor, J., Algebraic K-theory and quadratic forms, Invent. Math. 9 (1970), 318344.Google Scholar
12. Pfister, A., Quadratische Formen in beliebigen Korpern, Invent. Math. 1 (1966), 116132.Google Scholar
13. Scharlau, W., Quadratic forms, Queen's papers on pure and applied mathematics, 22, Queen's University, Kingston, Ont. (1969).Google Scholar
14. Witt, E., Théorie der quadratischen Formen in beliebigen Korpern, J. reine angew. Math. 176 (1937), 3144.Google Scholar