In this paper, we investigate isometric extension problem in general normed space. We prove that an isometry between spheres can be extended to a linear isometry between the spaces if and only if the natural positive ...In this paper, we investigate isometric extension problem in general normed space. We prove that an isometry between spheres can be extended to a linear isometry between the spaces if and only if the natural positive homogeneous extension is additive on spheres. Moreover, this conclusion still holds provided that the additivity holds on a restricted domain of spheres.展开更多
In this paper, we study the extension of isometries between the unit spheres of normed space E and lP(p 〉 1). We arrive at a conclusion that any surjective isometry between the unit sphere of normed space lP(p 〉 ...In this paper, we study the extension of isometries between the unit spheres of normed space E and lP(p 〉 1). We arrive at a conclusion that any surjective isometry between the unit sphere of normed space lP(p 〉 1) and E can be extended to be a linear isometry on the whole space lP(p 〉 1) under some condition.展开更多
In this paper, we prove that an into isometry form S(l(n)^∞) to S(E), which under some conditions, can be extended to be a linear isometry defined on the whole space. Therefore we improve the results of [Ding, ...In this paper, we prove that an into isometry form S(l(n)^∞) to S(E), which under some conditions, can be extended to be a linear isometry defined on the whole space. Therefore we improve the results of [Ding, G. G.: The isometric extension of an into mapping from the unit sphere S(l(2)^∞) to S(Lμ^1). Acta Mathematica Sinica, English Series, 22(6), 1721-1724 (2006)].展开更多
基金Supported by National Natural Science Foundation of China(Grant Nos.11301384,11371201,11201337 and11201338)
文摘In this paper, we investigate isometric extension problem in general normed space. We prove that an isometry between spheres can be extended to a linear isometry between the spaces if and only if the natural positive homogeneous extension is additive on spheres. Moreover, this conclusion still holds provided that the additivity holds on a restricted domain of spheres.
基金Supported by Natural Science Foundation of China (Grant No. 10571090)The second author is supported by NSFC (Grant No. 10571090)the Doctoral Program Foundation of Institution of Higher Education (Grant No. 20060055010)
文摘In this paper, we study the extension of isometries between the unit spheres of normed space E and lP(p 〉 1). We arrive at a conclusion that any surjective isometry between the unit sphere of normed space lP(p 〉 1) and E can be extended to be a linear isometry on the whole space lP(p 〉 1) under some condition.
基金Supported by National Natural Science Foundation of China (Grant No. 10871101)the Doctoral Pr0grame Foundation of Institution of Higher Education (Grant No. 20060055010)
文摘In this paper, we prove that an into isometry form S(l(n)^∞) to S(E), which under some conditions, can be extended to be a linear isometry defined on the whole space. Therefore we improve the results of [Ding, G. G.: The isometric extension of an into mapping from the unit sphere S(l(2)^∞) to S(Lμ^1). Acta Mathematica Sinica, English Series, 22(6), 1721-1724 (2006)].