@article{Chi2023, 
author = {Xiujiao Chi and Pengtong Li},
title = {Characterization of frame vectors for        A  -group-like unitary systems on Hilbert        C          ∗      -modules},
year = {2023},
journal = {AIMS Mathematics},
volume = {8},
number = {9},
pages = {22112-22126},
keywords = {A-group-like unitary systems, frame vectors, complete Bessel vectors, frame multiplicity, Hilbert C∗-modules},
url = {https://www.sciopen.com/article/10.3934/math.20231127},
doi = {10.3934/math.20231127},
abstract = {In this paper, the notion of an        A  -group-like unitary system on a Hilbert        C          ∗      -module is introduced and some basic properties are studied, where        A   is a unital        C          ∗      -algebra. Let        U   be such a unitary system. We prove that a complete Parseval frame vector for        U   can be dilated to a complete wandering vector. Also, it is shown that the set of all the complete Bessel vectors for        U   can be parameterized by the set of the adjointable operators in the double commutant of        U  , and that the frame multiplicity of        U   is always finite.}
}