PreprintarXiv licencearXiv
An Approximate-Diagonal Characterization of Amenable Actions on C*Algebras
Abstract
We introduce relative h-diagonals for crossed products ArtimesαΓ by discrete groups, which are positive-form approximate diagonals in the Haagerup tensor product taken relative to A. We show that α is amenable if and only if ArtimesαΓ admits a relative h-diagonal, an analogue of Johnson's theorem for L1(G).
Related
- Ergodic measures of intermediate entropies for amenable group actions with an approximate product property
- Generic Sharp Shift Embedding for Amenable Group Actions with the Uniform Rokhlin Property and Comparison
- Comparison and Almost Finiteness for Actions of Amenable Groups
- Equivariant 𝒵-stability for amenable actions
- An induction proof of strong NF\ for amenable group C*-algebras
BibTeX
@misc{fu2026approximatediagonal,
title = {{An Approximate-Diagonal Characterization of Amenable Actions on C*Algebras}},
author = {Zhengyu Fu},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.30821},
eprint = {2610.30821},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2610.30821},
}
RIS
TY - UNPB
TI - An Approximate-Diagonal Characterization of Amenable Actions on C*Algebras
AU - Zhengyu Fu
PY - 2026
DA - 2026/10/22
PB - arXiv
DO - 10.48550/arxiv.2610.30821
UR - https://arxiv.org/abs/2610.30821
AB - We introduce relative h-diagonals for crossed products Artimes_αΓ by discrete groups, which are positive-form approximate diagonals in the Haagerup tensor product taken relative to A. We show that α is amenable if and only if Artimes_αΓ admits a relative h-diagonal, an analogue of Johnson's theorem for L^1(G).
ER -