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Let ℳ be a semi-finite factor and let 𝓙(ℳ ) be the set of operators T in ℳ such that T = ETE for some finite projection E. We obtain a representation theorem for unitarily invariant norms on 𝓙(ℳ ) in terms of Ky Fan norms. As an application, we prove that the class of unitarily invariant norms on 𝓙(ℳ ) coincides with the class of symmetric gauge norms on a classical abelian algebra, which generalizes von Neumann's classical 1940 result on unitarily invariant norms on Mₙ(ℂ). As another application, Ky Fan's dominance theorem of 1951 is obtained for semi-finite factors.
Junsheng Fang, and Don Hadwin. "Unitarily invariant norms related to semi-finite factors." Studia Mathematica 229.1 (2015): 13-44. <http://eudml.org/doc/286316>.
@article{JunshengFang2015, abstract = {Let ℳ be a semi-finite factor and let 𝓙(ℳ ) be the set of operators T in ℳ such that T = ETE for some finite projection E. We obtain a representation theorem for unitarily invariant norms on 𝓙(ℳ ) in terms of Ky Fan norms. As an application, we prove that the class of unitarily invariant norms on 𝓙(ℳ ) coincides with the class of symmetric gauge norms on a classical abelian algebra, which generalizes von Neumann's classical 1940 result on unitarily invariant norms on Mₙ(ℂ). As another application, Ky Fan's dominance theorem of 1951 is obtained for semi-finite factors.}, author = {Junsheng Fang, Don Hadwin}, journal = {Studia Mathematica}, keywords = {unitarily invariant norms; semi-finite factors; s-numbers; Ky Fan norms}, language = {eng}, number = {1}, pages = {13-44}, title = {Unitarily invariant norms related to semi-finite factors}, url = {http://eudml.org/doc/286316}, volume = {229}, year = {2015}, }
TY - JOUR AU - Junsheng Fang AU - Don Hadwin TI - Unitarily invariant norms related to semi-finite factors JO - Studia Mathematica PY - 2015 VL - 229 IS - 1 SP - 13 EP - 44 AB - Let ℳ be a semi-finite factor and let 𝓙(ℳ ) be the set of operators T in ℳ such that T = ETE for some finite projection E. We obtain a representation theorem for unitarily invariant norms on 𝓙(ℳ ) in terms of Ky Fan norms. As an application, we prove that the class of unitarily invariant norms on 𝓙(ℳ ) coincides with the class of symmetric gauge norms on a classical abelian algebra, which generalizes von Neumann's classical 1940 result on unitarily invariant norms on Mₙ(ℂ). As another application, Ky Fan's dominance theorem of 1951 is obtained for semi-finite factors. LA - eng KW - unitarily invariant norms; semi-finite factors; s-numbers; Ky Fan norms UR - http://eudml.org/doc/286316 ER -