Supported by National Natural Science Foundation of China (Grant Nos. 10771175, 10801111 and 11101340);the Natural Science Foundation of Fujian Province (Grant No. 2010J05012) ;the Fundamental Research Funds for the Central Universities (Grant Nos. 2010121001 and 2011121039)
By a ball-covering B of a Banach space X, we mean that B is a collection of open (or closed) balls off the origin whose union contains the unit sphere of X; and X is said to have the ball-covering property provided ...
Supported by National Natural Science Foundation of China (Grant No. 10771175)
This paper presents two counterexamples about ball-coverings of Banach spaces and shows a new characterization of uniformly non-square Banach spaces via ball-coverings.
supported by National Natural Science Foundation of China (Grant Nos.10471114,10771175)
A normed space is said to have ball-covering property if its unit sphere can be contained in the union of countably many open balls off the origin. This paper shows that for every ε>0 every Banach space with a w*-sep...