The lattice Schäffer constant

Michael Alexánder Rincón Villamizar, Timur Oikhberg

For a Banach lattice $X$, its lattice Schäffer constant is defined by: \begin{gather*} λ^+(X)=\inf\{\max\{\|x+y\|,\|x-y\|\}\,\colon\,\|x\|=\|y\|=1,x,y\geq{\bf0}\}. \end{gather*} In…