In this article, the author presents some results of the isometric linear extension from some spheres in the finite dimensional space s（n）. Moreover, the author presents the representation for the onto isometric map...In this article, the author presents some results of the isometric linear extension from some spheres in the finite dimensional space s（n）. Moreover, the author presents the representation for the onto isometric mappings in the space s. It is obtained that if V is a surjective isometry from the space s onto s with V（0） = 0, then V must be real linear.展开更多
Yu introduced Property A on discrete metric spaces. In this paper, a relative Property A for a discrete metric space X with respect to a set Y and a map ρ_(X,Y) is defined. Some characterizations for relative Propert...Yu introduced Property A on discrete metric spaces. In this paper, a relative Property A for a discrete metric space X with respect to a set Y and a map ρ_(X,Y) is defined. Some characterizations for relative Property A are given. In particular, a discrete metric space with relative Property A can be coarse embedding into a Hilbert space under certain condition.展开更多
基金Supported by the National Natural Science Foundation of China (11001134 , 11126250)the Fundamental Research Funds for the Central Universitiesthe Tianjin Science & Technology Fund (20100820)
基金Supported by the National Science Foundation of China (10571090) The Research Fund for the Doctoral Program of Higher Education (20010055013)
文摘In this article, the author presents some results of the isometric linear extension from some spheres in the finite dimensional space s（n）. Moreover, the author presents the representation for the onto isometric mappings in the space s. It is obtained that if V is a surjective isometry from the space s onto s with V（0） = 0, then V must be real linear.
基金Supported by the National Natural Science Foundation of China(Grant No.11701301)
文摘Yu introduced Property A on discrete metric spaces. In this paper, a relative Property A for a discrete metric space X with respect to a set Y and a map ρ_(X,Y) is defined. Some characterizations for relative Property A are given. In particular, a discrete metric space with relative Property A can be coarse embedding into a Hilbert space under certain condition.
