Groups which are metrically weakly sofic with respect to word norms

Abstract

We consider metric versions of weak soficity, LEF and residual finiteness. The main results of the paper extend Glebsky and Rivera's characterization of weak soficity to the case of normally finitely generated groups with word metrics. Metric LEF and residual finiteness are also characterized in this class. We deduce that the free group ${\mathsf{F}}_2$ is not metrically weakly sofic with respect to its standard invariant word norm.

21 pages; small corrections in v2 (mainly in Section 3). arXiv admin note: substantial text overlap with arXiv:2311.16437