@article{Abrahamsen_2014, title={Strict U-Ideals and U-Summands in Banach Spaces}, volume={114}, url={https://www.mscand.dk/article/view/17108}, DOI={10.7146/math.scand.a-17108}, abstractNote={For a strict u-ideal $X$ in a Banach space $Y$ we show that the set of points in the dual unit ball $B_{X^{\ast }$, strongly exposed by points in the range $\it TY$ of the unconditional extension operator $T$ from $Y$ into the bidual $X^{\ast\ast}$ of $X$, is contained in the weak$^{\ast}$ denting points in $B_{X^{\ast }$. We also prove that a u-embedded space is a u-summand if and only if it contains no copy of $c_0$ if and only if it is weakly sequentially complete. }, number={2}, journal={MATHEMATICA SCANDINAVICA}, author={Abrahamsen, Trond A.}, year={2014}, month={May}, pages={216–225} }