Converse of representation-to-action without regularity for locally compact quantum groups
Determine whether, for a locally compact quantum group \mathbb{G} not assumed regular, every nondegenerate representation of the universal C*-algebra C^*_u(\mathbb{G}) on a Hilbert B-module E gives rise to a \mathbb{G}-action on E (i.e., a coaction of C_0^r(\mathbb{G}) on E acting trivially on B), thereby establishing the converse of Lemma \ref{lem:reg-needed?} without the regularity hypothesis.
References
It is unclear if the converse statement of Lemma \ref{lem:reg-needed?} is true without the assumption of regularity.
— Conformal transformations and equivariance in unbounded KK-theory
(2412.17220 - Masters et al., 23 Dec 2024) in Section 4.1 (Uniform quantum group equivariance), following Lemma \ref{lem:reg-needed?}