设F是特征不为2,3,5的任意域。令M2(F)是F上2×2全矩阵空间,S2(F)是F上2×2对称矩阵空间,T1及T2分别表示S2(F)及M2(F)中所有立方幂等阵的集合。Φ(F)表示从S2(F)到M2(F)所有单射φ的集合且φ满足:A-λAB∈T1→(A)-λφ(B)∈T2.给出Φ(F)中φ的形式。在此基础上又得到了S2(F)到自身相应的映射形式。
Let F be a field of chF≠2,3,5, M2 (F) be the space of all 2× 2 matrices over F, let S2 (F) be the space of all 2 × 2 symmetric matrices over F, T1 be the subset of S2 (F) consisting of all 2×2 tripotents matrices, T2 be the subset of M2 (F) consisting of all 2 ×2 tripotents matrices. The authors denote by Φ(F) the set of all injective maps from S2 (F) to M2 (F) satisfying A -λB∈ T1→φ(A) -λφ(B)∈T2, All injective mappings φ in the Φ(F) are characterized, and thereby all mappings from S2 (F) to itself are also characterized.