Previous |  Up |  Next

Article

Keywords:
Witt invariant; Brauer group; Brauer-Wall group; Witt equivalence
Summary:
The starting point of this note is the observation that the local condition used in the notion of a Hilbert-symbol equivalence and a quaternion-symbol equivalence — once it is expressed in terms of the Witt invariant — admits a natural generalisation. In this paper we show that for global function fields as well as the formally real function fields over a real closed field all the resulting equivalences coincide.
References:
[1] Czogała A. : Równoważność Hilberta ciał globalnych. volume 1969 of Prace Naukowe Uniwersytetu Śląskiego w Katowicach [Scientific Publications of the University of Silesia]. Wydawnictwo Uniwersytetu Śląskiego, Katowice, 2001. MR 1852938
[2] Koprowski P. : Local-global principle for Witt equivalence of function fields over global fields. Colloq. Math., 91(2):293–302, 2002. DOI 10.4064/cm91-2-8 | MR 1898636 | Zbl 1030.11017
[3] Koprowski P. : Witt equivalence of algebraic function fields over real closed fields. Math. Z., 242(2):323–345, 2002. DOI 10.1007/s002090100336 | MR 1980626 | Zbl 1067.11020
[4] Koprowski P. : Integral equivalence of real algebraic function fields. Tatra Mt. Math. Publ., 34:53–61, 2005. MR 2206911 | Zbl 1150.11420
[5] Lam T. Y. : Introduction to quadratic forms over fields. volume 67 of Graduate Studies in Mathematics. American Mathematical Society, Providence, RI, 2005. MR 2104929 | Zbl 1068.11023
[6] Perlis R., Szymiczek K., Conner P. E., Litherland R. : Matching Witts with global fields. In Recent advances in real algebraic geometry and quadratic forms (Berkeley, CA, 1990/1991; San Francisco, CA, 1991), volume 155 of Contemp. Math., pages 365–387. Amer. Math. Soc., Providence, RI, 1994. MR 1260721
[7] Szymiczek K. : Matching Witts locally and globally. Math. Slovaca, 41(3):315–330, 1991. MR 1126669 | Zbl 0766.11023
[8] Szymiczek K. : Witt equivalence of global fields. Comm. Algebra, 19(4):1125–1149, 1991. MR 1102331
[9] Szymiczek K. : Hilbert-symbol equivalence of number fields. Tatra Mt. Math. Publ., 11:7–16, 1997. MR 1475500 | Zbl 0978.11012
[10] Szymiczek K. : A characterization of tame Hilbert-symbol equivalence. Acta Math. Inform. Univ. Ostraviensis, 6(1):191–201, 1998. MR 1822530 | Zbl 1024.11022
Partner of
EuDML logo