Going-down functors and the Künneth formula for crossed products by étale groupoids
Going-down functors and the Künneth formula for crossed products by étale groupoids
复制标题
下落函子和 étale groupoids 交叉乘积的 Künneth 公式
DOI:
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发表时间:
2018
影响因子:
1.3
通讯作者:
Cl'ement Dell'Aiera
中科院分区:
文献类型:
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作者:
Christian Bonicke;Cl'ement Dell'Aiera
We study the connection between the Baum–Connes conjecture for an ample groupoid
G
G
with coefficient
A
A
and the Künneth formula for the
K
{\mathrm K}
-theory of tensor products by the crossed product
A
⋊
r
G
A\rtimes _r G
. To do so, we develop the machinery of going-down functors for ample groupoids. As an application, we prove that both the uniform Roe algebra of a coarse space which uniformly embeds in a Hilbert space and the maximal Roe algebra of a space admitting a fibered coarse embedding in a Hilbert space satisfy the Künneth formula. Additionally, we give an example of a space that does not admit a coarse embedding in a Hilbert space, but whose uniform Roe algebra satisfies the Künneth formula and provides a stability result for the Künneth formula using controlled
K
{\mathrm K}
-theory. As a byproduct of our methods, we also prove a permanence property for the Baum–Connes conjecture with respect to equivariant inductive limits of the coefficient algebra.