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arXiv · 2609.35567

Unique equivariant pseudo expectation and generalized Powers averaging for crossed product

Tattwamasi Amruram·Fatemeh Khosravi·Zahra Naghavi
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Abstract

Let $Γ$ be a countable discrete group and let $A$ be a unital $Γ$-simple $Γ$-$C^*$-algebra. We prove that $A\rtimes_rΓ$ has the generalized Powers averaging property if and only if the canonical map $A\rtimes_rΓ\to I_Γ(A)$ 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 $A$.

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Tattwamasi Amruram, Fatemeh Khosravi, Zahra Naghavi. 2026-09-28. Unique equivariant pseudo expectation and generalized Powers averaging for crossed product. https://arxiv.org/abs/2609.35567

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