文摘
Let D be a division algebra finite-dimensional over its center C , 惟:=Mm(D), the m×m matrix algebra over D , and V be a vector space over C . We characterize all n -linear forms on 惟 in terms of reduced traces and elementary operators. For m>1, it is proved that a bilinear form B:惟×惟→V vanishes on zero products of xy and yx if and only if there exist linear maps g,h:惟→V such that B(x,y)=g(xy)+h(yx) for all x,y∈惟. As an application, a bilinear form B is completely characterized if B(x,y)=0 whenever x,y∈惟 satisfy xy+尉yx=0, where 尉 is a fixed nonzero element in C.