Morita equivalence of two ${\ell }^p$ Roe-type algebras

Abstract

Given a metric space with bounded geometry, one may associate with it the ${\ell }^p$ uniform Roe algebra and the ${\ell }^p$ uniform algebra, both containing information about the large scale geometry of the metric space. We show that these two Banach algebras are Morita equivalent in the sense of Lafforgue for $1\le p<\infty$. As a consequence, these two Banach algebras have the same $K$-theory. We then define an ${\ell }^p$ uniform coarse assembly map taking values in the $K$-theory of the ${\ell }^p$ uniform Roe algebra and show that it is not always surjective.

arXiv comment20 pages. Final version accepted for publication in JNCG. Main changes from the previous version: (1) edited the second half of the proof of theorem 3.1; (2) added remark 2.14