scientific article; zbMATH DE number 803186

Publication date: 8 October 1995

Title: zbMATH Open Web Interface contents unavailable due to conflicting licenses.

spheres quadratic forms Witt rings Pythagoras number formally real fields Borsuk-Ulam Theorem anisotropic quadratic form non-formally real fields level of a field \(u\)-invariants homogeneous Nullstellensatz for \(p\)-fields computation of the levels of projective spaces existence of \(K\)-rational points for systems of forms numerical invariants of fields Tsen-Lang theory of \(C_ i\)-fields

Mathematics Subject Classification ID

Quadratic forms over general fields (11E04) Algebraic theory of quadratic forms; Witt groups and rings (11E81) Fields related with sums of squares (formally real fields, Pythagorean fields, etc.) (12D15) Research exposition (monographs, survey articles) pertaining to number theory (11-02) Research exposition (monographs, survey articles) pertaining to algebraic geometry (14-02) Skew fields, division rings (12E15) Classical topics in algebraic topology (55M99)

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