For a dense set of equivalent norms , a non - reflexive Banach space contains a triangle with no Chebyshev center
نویسنده
چکیده
Let X be a non-reflexive real Banach space. Then for each norm | · | from a dense set of equivalent norms on X (in the metric of uniform convergence on the unit ball of X), there exists a three-point set that has no Chebyshev center in (X, | · |). This result strengthens theorems by Davis and Johnson, van Dulst and Singer, and Konyagin.
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تاریخ انتشار 2010