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arXiv · 0707.3754

A hermitian analogue of the Broecker-Prestel theorem

Vincent Astier·Thomas Unger
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Abstract

The Broecker-Prestel local-global principle characterizes weak isotropy of quadratic forms over a formally real field in terms of weak isotropy over the henselizations and isotropy over the real closures of that field. A hermitian analogue of this principle is presented for algebras of index at most two. An improved result is also presented for algebras with a decomposable involution, algebras of pythagorean index at most two, and algebras over SAP and ED fields.

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Vincent Astier, Thomas Unger. 2007-07-25. A hermitian analogue of the Broecker-Prestel theorem. https://doi.org/10.1016/s0019-3577(09)00007-x

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