Abstract
Let K be a global function field of characteristic 2. For each non-trivial place v of K, let \( K_{v} \) be the completion of K at v. We show that if two non-degenerate quadratic forms are similar over every \( K_{v} \), then they are similar over K. This provides an analogue of the version for characteristic not 2 previously obtained by T.Ono.
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Baeza, R.: Comparing \(u\)-invariants of fields of characteristic \(2\). Bol. Soc. Brasil. Mat. 13(1), 105–114 (1982)
Berhuy, G., Frings, C., Tignol, J.-P.: Galois cohomology of the classical groups over imperfect fields. J. Pure Appl. Algebra 211(2), 307–341 (2007)
Cortella, A.: Le principe de Hasse pour les similitudes de formes quadratiques et hermitiennes. In: Théorie des nombres, Année 1991/1992, Publ. Math. Fac. Sci. Besançon, 1–11. Univ. Franche-Comté, Besançon (1992)
Cortella, A.: Un contre-exemple au principe de Hasse pour les similitudes de formes bilinéaires. C. R. Acad. Sci. Paris Sér. I Math. 317(8), 707–710 (1993)
Elman, R., Karpenko, N., Merkurjev, A.: The algebraic and geometric theory of quadratic forms. Amer. Math. Soc. Coll. Publ. 56. Amer. Math. Soc., Providence, RI (2008)
Gille, P.: Invariants cohomologiques de Rost en caractéristique positive. K-Theory 21(1), 57–100 (2000)
Gille, P., Szamuely, T.: Central simple algebras and Galois cohomology. Camb. Stud. in Adv. Math., vol. 165. Cambridge University Press, Cambridge (2017)
Kato, K.: Galois cohomology of complete discrete valuation fields. In: Algebraic \(K\)-theory, Part II (Oberwolfach, 1980), Lect. Notes in Math. 967: 215–238. Springer, Berlin (1982)
Knus, M.-A.: Quadratic and Hermitian forms over rings. Grun. der Math. Wiss., vol. 294. Springer, Berlin (1991)
Knus, M.-A., Merkurjev, A., Rost, M., Tignol, J.-P.: The book of involutions. Amer. Math. Soc. Coll. Publ. 44. Am. Math. Soc., Providence, RI (1998)
Lewis, D., Unger, T., Van Geel, J.: The Hasse principle for similarity of Hermitian forms. J. Algebra 285(1), 196–212 (2005)
Mammone, P., Tignol, J.-P., Wadsworth, A.: Fields of characteristic \(2\) with prescribed \(u\)-invariants. Math. Ann. 290(1), 109–128 (1991)
Milne, J.S.: Duality in the flat cohomology of a surface. Ann. Sci. École Norm. Sup. (4) 9(2), 171–201 (1976)
O’Meara, O.: Introduction to quadratic forms. Clas. in Math. Springer, Berlin (2000)
Ono, T.: Arithmetic of orthogonal groups. J. Math. Soc. Jpn. 7, 79–91 (1955)
Pollak, B.: Orthogonal groups over global fields of characteristic \(2\). J. Algebra 15, 589–595 (1970)
Prasad, G., Rapinchuk, A.: Local-global principles for embedding of fields with involution into simple algebras with involution. Comment. Math. Helv. 85(3), 583–645 (2010)
Acknowledgements
The author is supported by National Natural Science Foundation of China (No.11701352) and Shantou University Scientific Research Foundation for Talents (No.130-760188). The author thanks Yong Hu for helpful discussions.
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Communicated by Jacques Helmstetter
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Wu, Z. Similarity of Quadratic Forms Over Global Fields in Characteristic 2. Adv. Appl. Clifford Algebras 29, 86 (2019). https://doi.org/10.1007/s00006-019-1006-8
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DOI: https://doi.org/10.1007/s00006-019-1006-8