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Unique equivariant pseudo expectation and generalized Powers averaging for crossed product
Abstract
Let Γ be a countable discrete group and let A be a unital Γ-simple Γ-C*-algebra. We prove that ArtimesrΓ has the generalized Powers averaging property if and only if the canonical map ArtimesrΓ→ IΓ(A) is the unique Γ-equivariant pseudo-expectation. We also show that this averaging property lifts to IΓ(A)rtimesrΓ, with the averaging coefficients still belonging to A.
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BibTeX
@misc{amrutam2026unique,
title = {{Unique equivariant pseudo expectation and generalized Powers averaging for crossed product}},
author = {Tattwamasi Amrutam and Fatemeh Khosravi and Zahra Naghavi},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2609.35567},
eprint = {2609.35567},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2609.35567},
}
RIS
TY - UNPB
TI - Unique equivariant pseudo expectation and generalized Powers averaging for crossed product
AU - Tattwamasi Amrutam
AU - Fatemeh Khosravi
AU - Zahra Naghavi
PY - 2026
DA - 2026/09/28
PB - arXiv
DO - 10.48550/arxiv.2609.35567
UR - https://arxiv.org/abs/2609.35567
AB - Let Γ be a countable discrete group and let A be a unital Γ-simple Γ-C^*-algebra. We prove that Artimes_rΓ has the generalized Powers averaging property if and only if the canonical map Artimes_rΓ→ I_Γ(A) is the unique Γ-equivariant pseudo-expectation. We also show that this averaging property lifts to I_Γ(A)rtimes_rΓ, with the averaging coefficients still belonging to A.
ER -