Some remarks on universality properties of ${\ell }_{\infty }/c_0$

Abstract

We prove that if continuum is not a Kunen cardinal, then there is a uniform Eberlein compact space $K$ such that the Banach space $C(K)$ does not embed isometrically into ${\ell }_{\infty }/c_0$. We prove a similar result for isomorphic embeddings. We also construct a consistent example of a uniform Eberlein compactum whose space of continuous functions embeds isomorphically into ${\ell }_{\infty }/c_0$, but fails to embed isometrically. As far as we know it is the first example of this kind.