On isometric full embeddings of symplectic dual polar spaces into Hermitian dual polar spaces
โ Scribed by Bart De Bruyn
- Publisher
- Elsevier Science
- Year
- 2009
- Tongue
- English
- Weight
- 192 KB
- Volume
- 430
- Category
- Article
- ISSN
- 0024-3795
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โฆ Synopsis
Let n 2, let K, K be fields such that K is a quadratic Galoisextension of K and let ฮธ denote the unique nontrivial element in Gal(K /K). Suppose the symplectic dual polar space DW (2n -1, K) is fully and isometrically embedded into the Hermitian dual polar space DH(2n -1, K , ฮธ). We prove that the projective embed- ding of DW (2n -1, K) induced by the Grassmann-embedding of DH(2n -1, K , ฮธ) is isomorphic to the Grassmann-embedding of DW (2n -1, K). We also prove that if n is even, then the set of points of DH(2n -1, K , ฮธ) at distance at most n 2 -1 from DW (2n -1, K) is a hyperplane of DH(2n -1, K , ฮธ) which arises from the Grassmann-embedding of DH(2n -1, K , ฮธ).
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